As filed with the U.S. Securities and Exchange Commission on February 11, 2026.

Registration No. 333—    

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM F-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

MANGO FINANCIAL GROUP LIMITED

(Exact name of registrant as specified in its charter)

Units 2305-2306, 23/F, Grand Millennium Plaza

181 Queen’s Road, Central,

Sheung Wan, Hong Kong

Tel: (852) 2532 3984

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Cheung Kam Fai, Chief Executive Officer and Director

Units 2305-2306, 23/F, Grand Millennium Plaza

181 Queen’s Road, Central,

Sheung Wan, Hong Kong

Tel: (852) 2532 3984

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after (i) this registration statement is declared effective and (ii) upon completion of the applicable transactions described in the enclosed proxy statement/prospectus.

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer) ☐

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer) ☐

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933.

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the Registration Statement shall become effective on such date as the SEC, acting pursuant to Section 8(a), may determine.

TABLE OF CO-REGISTRANTS

(1) The Co-Registrant has the following principal executive office:

Cayson Acquisition Corp

205 West 37th Street

New York, New York 10018

(2) The agent for service for the Co-Registrant is:

Yawei Cao, Chairman and Chief Executive Officer

Cayson Acquisition Corp

205 West 37th Street

New York, New York 10018

Tel: (203) 998-5540

The information in this preliminary proxy statement/prospectus is not complete and may be changed. The registrant may not sell the securities described in this preliminary proxy statement/prospectus until the registration statement filed with the U.S. Securities and Exchange Commission, of which this proxy statement/prospectus is a part, is declared effective. This preliminary proxy statement/prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

PRELIMINARY PROXY STATEMENT/PROSPECTUS
SUBJECT TO COMPLETION, DATED FEBRUARY 11, 2026

PROXY STATEMENT
FOR THE EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF
CAYSON ACQUISITION CORP

PROSPECTUS
FOR 8,453,000 ORDINARY SHARES OF
MANGO FINANCIAL GROUP LIMITED

_____________________________________________

CAYSON ACQUISITION CORP
205 W 37^th St.
New York, New York 10018

LETTER TO CAYSON SHAREHOLDERS

Dear Cayson Acquisition Corp Shareholder:

You are cordially invited to attend an extraordinary general meeting (the “Meeting”) of Cayson Acquisition Corp (“Cayson”) at [●], Eastern Time, on [●], 2026, virtually via live webcast at [●] and via teleconference at [●] (U.S. toll free) or [●] (international toll free) (in each case using participant code [●]), or at such other time and place to which the Meeting may be adjourned. See “Frequently Used Terms” in the accompanying proxy statement/prospectus for definitions of certain terms used in this letter.

Business Combination

Cayson is a blank check company incorporated on May 27, 2024 as a Cayman Islands exempted company for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization, or similar business combination with one or more businesses.

On July 11, 2025, Cayson entered into an Agreement and Plan of Merger, as amended (as may be further amended, restated or supplemented, the “Business Combination Agreement”) with Mango Financial Group Limited, a Cayman Islands exempted company (“Mango”), North Water Investment Group Holdings Limited (“North Water”), the parent company of Mango Financial Limited (“Mango Financial”), and Mango Temp Limited, a Cayman Islands exempted company and a wholly-owned subsidiary of Mango (“Merger Sub”), which provides for a business combination between Cayson and Mango (the “Business Combination”). A copy of the Business Combination Agreement is attached to the accompanying proxy statement/prospectus as Annex A.

Mango is not a Chinese operating company but a Cayman Islands holding company with operations conducted by its subsidiaries in the Hong Kong Special Administrative Region of the People’s Republic of China.

In accordance with the Business Combination Agreement, as further described in the accompanying proxy statement/prospectus, the Business Combination will be accomplished by way of the following transaction steps:

The Business Combination values Mango at $140,000,000, based on 14,000,000 Mango Ordinary Shares to be outstanding immediately prior to the Business Combination and an assumed value of $10.00 per Mango Ordinary Share. As a result of the Business Combination, Cayson will become a wholly owned subsidiary of Mango, the security holders of Cayson immediately prior to the Effective Time will become security holders of Mango, and Mango will become a public holding company conducting the business of Mango Financial. As used in this proxy statement/prospectus, “New Mango” refers to Mango following the consummation of the Business Combination.

The Cayson Ordinary Shares, Cayson Units and Cayson Rights are currently listed on the Nasdaq Global Market under the symbols “CAPN,” “CAPNU” and “CAPNR,” respectively. Mango intends to apply to list its Mango Ordinary Shares on Nasdaq under the symbol “[●].” It is a condition of the consummation of the Business Combination that the listing of the Mango Ordinary Shares has been approved by Nasdaq, subject only to official notice of issuance thereof, but there can be no assurance such listing condition will be met or that Mango will obtain such approval from Nasdaq. If such listing condition is not met or if such approval is not obtained, the Business Combination will not be consummated, unless the corresponding condition set forth in the Business Combination Agreement is waived by the parties. Mango will not have any outstanding units or rights following the completion of the Business Combination.

Following the listing of the Mango Ordinary Shares, Mango will have one class of shares, Mango Ordinary Shares. Holders of Ordinary Shares are entitled to one vote per share.

Founded in 1970 during Hong Kong’s industrial boom, Mango Financial was among the first non-foreign securities firms and a founding member of the Far East Exchange—the predecessor of the Hong Kong Stock Exchange. Over the past five decades, Mango Financial has evolved from a traditional trading house into a full-service financial institution, offering investment banking, financial advisory, asset management, and securities underwriting and trading.

Following the consummation of the Business Combination, Mango and its subsidiaries (“Mango Group”) will not have any subsidiaries or business operations in mainland China. However, Mango is aware that in recent years, the PRC government has initiated a series of regulatory actions and statements to regulate business operations in the PRC with little advance notice, including cracking down on illegal activities in the securities market, enhancing supervision over China-based companies listed overseas using a variable interest entity structure, adopting new measures to extend the scope of cybersecurity reviews, and expanding the efforts in anti-monopoly enforcement. It is uncertain what potential impact such modified or new laws and regulations will have on Mango’s daily business operations, its ability to accept foreign investments and the listing of its securities on a U.S. or other foreign exchanges. These actions could result in a material change in its operations and/or the value of its securities and could significantly limit or completely hinder its ability to offer or continue to offer its securities to investors. Additionally, on February 17, 2023, the China Securities Regulatory Commission (the “CSRC”) promulgated the Trial Administrative Measures of the Overseas Securities Offering and Listing by Domestic Companies (the “Trial Measures”), and five supporting guidelines, which became effective on March 31, 2023. The Trial Measures, which reformed the existing regulatory regime for overseas offering and listing of securities by PRC domestic companies and both direct and indirect overseas offering and listing of securities by PRC domestic companies, imposes a filing-based regulatory regime. According to the Trial Measures, if an issuer meets both of the following criteria, the overseas securities offering and listing conducted by such issuers shall be deemed as indirect overseas offering and listing, and filings with the CSRC pursuant to the Trial Measures’ requirements shall be submitted within three working days following its submission of application for an initial public offering or listing: (i) more than 50% of the issuer’s operating revenue, total profit, total assets or net assets as documented in its audited consolidated financial statements for the most recent fiscal year is accounted for by domestic companies; and (ii) the main parts of the issuer’s business activities are conducted in China, or its main places of business are located in China, or the senior managers in charge of its business operations and majority of the issuer’s management are Chinese citizens or domiciled in China. As of the date of this proxy statement/prospectus, neither Mango Financial nor Mango, whether prior to or after the consummation of the Business Combination, believes that it meets the criteria for CSRC filing, on the basis that (i) neither Mango Financial nor Mango has or will have any subsidiaries or business operations in mainland China; (ii) none of Mango Financial’s or Mango’s operating revenues, total profits, total assets or net assets is or will be accounted for by any subsidiaries based in mainland China; and (iii) no issuance or sale of the securities of Mango Financial or Mango has been or will be made directly or indirectly within mainland China. For the fiscal year ended December 31, 2023 and 2024, approximately nil and nil Mango’s total revenue was generated from clients located in Mainland China for engagements in which Mango or its subsidiaries acted as a sponsor, placement agent, or underwriter. For the six months ended June 30, 2024 and 2025, approximately nil and nil of Mango’s total revenue was generated from clients located in Mainland China for engagements in which Mango or its subsidiaries acted as a sponsor, placement agent, or underwriter.

PRC regulators have been increasingly focused on regulation in areas of data security and data protection and the PRC regulatory requirements regarding cybersecurity are constantly evolving. Various regulatory bodies in China, specifically the Cyberspace Administration of China (the “CAC”), have enforced data privacy and protection laws and regulations with varying and evolving standards and interpretations. On December 28, 2021, the CAC and 12 other relevant PRC government authorities published the amended Cybersecurity Review Measures (the “New CAC Measures”), which came into effect on February 15, 2022 and replaced the cybersecurity review measures issued in April 2020. The New CAC Measures provide that a “network platform operator” that possesses personal information of more than one million users and seeks to list its securities overseas must apply for a cybersecurity review. Further, the relevant PRC governmental authorities may initiate a cybersecurity review against any company if they determine certain network products, services, or data processing activities of such company affect or may affect national security, or such company be construed as operators of critical information infrastructure purchasing network products and services. Mango Financial does not collect, process or use personal information of entities or individuals other than what is necessary for its business and does not disseminate such information, and does not conduct any data processing activities in mainland China. Neither Mango Financial nor Mango believes that it is required to obtain clearance from the CAC under the New CAC Measures. However, Mango faces uncertainties as to the interpretation or implementation of such regulations or rules, and if required, whether such clearance can be timely obtained, or at all. In the future, if Mango and/or its subsidiaries are required to obtain any permission or approval from or complete any filing procedure with the CSRC, the CAC, or other PRC governmental authorities in connection with the Business Combination under the PRC law, Mango and/or its subsidiaries may be fined or subject to other sanctions, and Mango and/or its subsidiaries’ business and reputation, financial condition, and results of operations may be materially and adversely affected. Any actions by the PRC government to exert more influence and control over offerings that are conducted overseas and/or foreign investments in Hong Kong-based issuers (including businesses whose operations are in Hong Kong) could significantly limit or completely hinder Mango’s ability to offer or continue to offer securities to investors and cause the value of its securities to significantly decline or be worthless. For a detailed description of the risks related to doing business in Hong Kong and Mango’s securities, see “Risk Factors — Risks Related to Doing Business in the Jurisdiction in which we Operate — If we and our subsidiaries were to be required to comply with cybersecurity, data privacy, data protection, or any other PRC laws and regulations related thereto and we and our subsidiaries are unable to comply with such PRC laws and regulations, our financial condition, and results of operations may be materially and adversely affected.”

Mango’s securities will be prohibited from trading on a national securities exchange or in the over-the-counter trading market in the United States under the Holding Foreign Companies Accountable Act (the “HFCAA”) if the Securities and Exchange Commission (the “SEC”) determines that Mango has filed audit reports issued by a registered public accounting firm that has not been subject to inspections by the Public Company Accounting Oversight Board (the “PCAOB”) for two consecutive years. On December 16, 2021, the PCAOB issued a report to notify the SEC of its determination that the PCAOB was unable to inspect or investigate completely registered public accounting firms headquartered in mainland China and Hong Kong. On December 15, 2022, the PCAOB announced that it was able to secure complete access to inspect and investigate PCAOB-registered public accounting firms headquartered in mainland China and Hong Kong in 2022. Mango’s auditor, ASSENTSURE PAC, the independent registered public accounting firm, as an auditor of companies that are traded publicly in the United States and a firm registered with the PCAOB, is subject to laws in the United States pursuant to which the PCAOB conducts regular inspections to assess ASSENTSURE PAC’s compliance with applicable professional standards. ASSENTSURE PAC, is headquartered in Singapore. As of the date of this proxy statement/prospectus, ASSENTSURE PAC is not included in the list of firms identified by PCAOB issued in December 2021. Each year, the PCAOB will determine whether it can inspect and investigate completely audit firms in mainland China and Hong Kong, among other jurisdictions. If the PCAOB determines in the future that it no longer has full access to inspect and investigate completely accounting firms in mainland China and Hong Kong and Mango uses an accounting firm headquartered in one of these jurisdictions to issue an audit report on its financial statements filed with the SEC, Mango would be identified as a Commission-Identified Issuer following the filing of the annual report on Form 20-F for the relevant fiscal year. In accordance with the HFCAA, Mango’s securities would be prohibited from being traded on a national securities exchange or in the over-the-counter trading market in the United States if it is identified as a Commission-Identified Issuer for two consecutive years in the future. If Mango’s securities are prohibited from trading in the United States, there is no certainty that it will be able to list on a non-U.S. exchange or that a market for its securities will develop outside of the United States. In the event of such prohibition, the Nasdaq may determine to delist Mango’s securities. The delisting of Mango’s securities, or the threat of their being delisted, may materially and adversely affect the value of your investment. For more details, see “Risk Factors —  Risks Related to Doing Business in the Jurisdiction in which we Operate — Although the audit report included in this proxy statement/prospectus is prepared by U.S. auditors who are currently inspected by the PCAOB, there is no guarantee that future audit reports will be prepared by auditors inspected by the PCAOB and, as such, in the future, investors may be deprived of the benefits of such inspection. Furthermore, trading in our securities may be prohibited under the Holding Foreign Companies Accountable Act (“HFCAA”) if the SEC subsequently determines our audit work is performed by auditors that the PCAOB is unable to inspect or investigate completely, and as a result, U.S. national securities exchanges, such as the Nasdaq, may determine to delist our securities. Furthermore, on December 23, 2022, the Accelerating Holding Foreign Companies Accountable Act (“AHFCAA”) was enacted, which amended the HFCAA by requiring the SEC to prohibit an issuer’s securities from trading on any U.S. stock exchanges if its auditor is not subject to PCAOB inspections for two consecutive years instead of three, thus reducing the time before the securities may be prohibited from trading or delisted.”

Because of the Mango Group’s substantial operations in Hong Kong and given that (i) the PRC government has significant oversight and authority over the conduct of business in Hong Kong generally and (ii) there are significant risks and uncertainties regarding the enforcement of PRC laws and regulations as the laws, rules and regulations in the PRC can change quickly with little advance notice, PRC laws, rules and regulations could become applicable to the Mango Group’s business in Hong Kong, and the Mango Group could become subject to such oversight, discretion or control, including over overseas offerings of securities and/or foreign investments, its operations may be materially and adversely affected, Mango’s ability to offer or continue to offer securities to investors may be significantly limited or completely hindered, and the value of Mango’s securities could significantly decline or become worthless, which would materially affect the interests of the Mango Group’s investors. Furthermore, while Mango Group does not believe the recent statements and regulatory actions by the PRC government and regulatory authorities in Hong Kong, such as those related to data security or anti-monopoly concerns, have had any impact on it, these statements and regulatory actions could have a significant impact on the Mango Group’s ability to conduct its business, accept foreign investments, or seek or maintain listing on Nasdaq or another U.S. or foreign stock exchange. Any actions by the PRC government or regulatory authorities in Hong Kong to exert more oversight and control over offerings that are conducted overseas by, and/or foreign investment in, issuers that are based in mainland China or Hong Kong could significantly limit or completely hinder Mango’s ability to offer or continue to offer securities to investors and cause the value of Mango’s securities to significantly decline or become worthless. For a more detailed description on the related risks, see “Risk Factors—Risks Related to Doing Business in the Jurisdiction in which we Operate — The PRC government may intervene or influence the Hong Kong operations of an offshore company, such as us, at any time, which could result in a material change in our operations and/or the value of our Ordinary Shares. If the PRC government exerts more oversight and control over offerings that are conducted overseas and/or foreign investment in Hong Kong-based issuers and we were to be subject to such oversight and control, it may limit or completely hinder our ability to offer or continue to offer securities to investors and cause the value of our securities to significantly decline or be worthless,” “Risk Factors— Risks Related to Doing Business in the Jurisdiction in which we Operate — Our financial condition, results of operations, the value of our Ordinary Shares and/or our ability to offer or continue to offer securities to investors may be materially and adversely affected by existing or future PRC laws and regulations which may become applicable to us and our subsidiaries,” “Risk Factors— Risks Related to Doing Business in the Jurisdiction in which we Operate —We and our subsidiaries face uncertainties arising from the possible revision regarding the interpretation and implementation of current and any future PRC laws and regulations related to part of our business operations,” and “Risk Factors— Risks Related to Doing Business in the Jurisdiction in which we Operate — If we were to be required to obtain any permission or approval from or complete any filing procedures with the CSRC, the CAC, or other PRC governmental authorities in connection with this offering under the PRC laws, we may be fined or subject to other sanctions.”

Furthermore, substantially all the individuals who are expected to serve as Mango’s directors, officers and members of senior management, including but not limited to Jialing Zhang, Cheung Kam Fai, Zhao Pang, Yuguo Chen, Tony Tang and Chi Kwan Ying, are located in Hong Kong or Mainland China, which makes it more difficult (i) to serve legal process within the United States upon these individuals, (ii) to obtain information from these individuals necessary for investigations or lawsuits, (iii) to enforce, both in and outside the United States, judgments obtained in U.S. courts against these individuals in any action, including actions based upon the civil liability provisions of U.S. federal or state securities laws, and (iv) to bring an original action in a Hong Kong court to enforce liabilities against these individuals based upon the U.S. federal securities laws. For a more detailed description on the related risks, see “Risk Factors—Risks Related to Doing Business in the Jurisdiction in which we Operate — You may incur additional costs and procedural obstacles in effecting service of legal process, enforcing foreign judgments or bringing actions in Hong Kong against us or our management named in this proxy statement/prospectus based on Hong Kong laws.”

Mango has no plans to declare cash dividends in the near term, but as a holding company, Mango may rely on dividends from its subsidiaries for cash requirements, including any payment of dividends to its shareholders, and neither Mango nor its subsidiaries has maintained cash management policies which dictate the purpose, amount and procedure of cash transfers between the entities. The ability of its subsidiaries to pay dividends to Mango, however, is subject to the debt they incur on their own behalf and/or laws and regulations applicable to them. As of the date of this proxy statement/prospectus, Mango has not declared or paid any dividends or distributions on equity to its shareholders. Mango may also make loans and additional capital contribution to its subsidiaries or branches, subject to certain requirements under the applicable laws.

In connection with the Business Combination, certain related agreements have been, or will be, entered into on or prior to the date of the Closing, including (i) the Lock-Up Agreement, (ii) the Registration Rights Agreement, (iii) the Indemnification Escrow Agreement, and (iv) the Earnout Escrow Agreement. For additional information, see “Proposal No. 1: The Business Combination Proposal —Related Agreements—Transaction Documents” in the accompanying proxy statement/prospectus.

The Business Combination Agreement provides that the obligations of the parties to consummate the Merger are conditioned on, among other things, (i) certain required consents and approvals from governmental authorities, including approval of the SFC, having been obtained, and there being no agreement between Mango or Cayson and any governmental authority pursuant to which Mango or Cayson has agreed not to consummate the Business Combination, (ii) the registration statement filed by Mango with the SEC, of which the accompanying proxy statement/prospectus forms a part, having become effective, (iii) the approval of the proposals to be presented at the Meeting having been obtained, (iv) the listing of the Mango Ordinary Shares having been approved by Nasdaq, subject only to official notice of issuance thereof, (v) no governmental authority of competent jurisdiction having enacted or issued any law (whether temporary, preliminary or permanent), in each case that is in effect and which has the effect of restraining, enjoining or prohibiting the consummation of the transaction, (vi) the Restructuring having been consummated, (vii) the PIPE Financing having been consummated, (viii) Cayson having at least $5,000,001 of net tangible assets, (ix) Mango and Merger Sub, on one hand, and Cayson, on the other hand, having each performed and complied in all material respects with the obligations, covenants and agreements required by the Business Combination Agreement to be performed or complied with by it at or prior to the Effective Time, and (x) the representations and warranties in the Business Combination Agreement of Mango and Merger Sub, on one hand, and Cayson, on the other hand, being true and correct subject to customary bringdown standards. In addition, the obligations of Mango to consummate the Business Combination are conditioned upon, among other items, there having been no “Material Adverse Effect” on Cayson since the date of the Business Combination Agreement, and the obligations of Cayson to consummate the Business Combination are conditioned upon, among other items, there having been no “Material Adverse Effect” on Mango since the date of the Business Combination Agreement. The Business Combination Agreement is also subject to the satisfaction or waiver of certain other closing conditions as described in the accompanying proxy statement/prospectus.

There can be no assurance that the parties to the Business Combination Agreement would waive any such provision of the Business Combination Agreement if it is not satisfied as of the time of satisfaction of all other conditions precedent to the Merger.

Extraordinary General Meeting

At the Meeting, you will be asked to consider and vote upon:

The Merger may be consummated only if the (i) Business Combination Proposal and (ii) the Merger Proposal (collectively, the “Condition Precedent Proposals”) are approved at the Meeting. The approval of each of the Condition Precedent Proposals is cross-conditioned on the approval of the other. The approval of the Nasdaq Proposal and the Non-Binding Governance Proposals also are conditioned on the Condition Precedent Proposals. None of the proposals are conditioned on the approval of the Nasdaq Proposal or the Non-Binding Governance Proposals. However, the Business Combination will not be consummated unless all the proposals are approved or the corresponding condition in the Business Combination Agreement is waived by the parties to such agreement. If the Adjournment Proposal is presented, the other proposals will not be presented. The Non-Binding Governance Proposals are constituted of non-binding advisory proposals. Each of these proposals is more fully described in the accompanying proxy statement/prospectus, which each shareholder is encouraged to read carefully and in its entirety.

Pursuant to Cayson’s M&A, the holders of Public Shares, excluding Cayson Holding LP (“Cayson Holding”) and Yawei Cao (together with Cayson Holding, the “Sponsors”) and Cayson’s officers and directors, may elect to have all or a portion of such shareholder’s Public Shares redeemed for cash if the Business Combination is consummated, provided that no such shareholder acting together with any affiliate of his or any other person with whom he is acting in concert or as a partnership, syndicate, or other group for the purposes of acquiring, holding, or disposing of shares of Cayson may exercise this redemption right with respect to more than 15% of the Public Shares without the Cayson’s prior consent. You will be entitled to receive cash for any Public Shares to be redeemed only if you:

Public Shareholders must complete the procedures for electing to redeem their Public Shares in the manner described above prior to 5:00 p.m., Eastern Time, on [●], 2026 (two (2) business days before the Meeting) in order for their shares to be redeemed. Public Shareholders may elect to redeem their Public Shares whether they vote “for” or “against” or do not vote at all on the Business Combination Proposal or the other proposals to be voted upon at the Meeting.

If you hold Cayson Ordinary Shares through Cayson Units, you must elect to separate your Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights prior to exercising your redemption rights with respect to the Public Shares. If you hold your Cayson Units in an account at a brokerage firm or bank, you must notify your broker or bank that you elect to separate the Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights, or if you hold Cayson Units registered in your own name, you must contact Continental, Cayson’s transfer agent, directly and instruct it to do so.

Notwithstanding the foregoing, no holder of Public Shares, acting individually or together with any affiliate of such holder or any other person with whom such holder is acting in concert or as a partnership, syndicate, or other group (as defined in Section 13(d)(3) of the Exchange Act) for the purposes of acquiring, holding, or disposing of Cayson Ordinary Shares, may exercise this redemption right with respect to more than 15% of the Public Shares without Cayson’s prior consent. Accordingly, all Public Shares in excess of that 15% limit will not be redeemed for cash.

If the Business Combination is not consummated, the Public Shares will be returned to their respective holders, brokers, or banks. If the Business Combination is consummated, and if a Public Shareholder properly exercises its right to redeem all or a portion of the Public Shares that they hold and timely delivers its shares to Continental, Cayson will redeem such Public Shares for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account established at the consummation of Cayson’s Initial Public Offering (the “trust account”), including any interest earned on the funds held in the trust account and not previously released to Cayson to pay its taxes, divided by the number of then outstanding Public Shares, calculated as of two (2) business days prior to the consummation of the Business Combination. For illustrative purposes, as of [__], 2026, this would have amounted to approximately $[__] per issued and outstanding Public Share. If a Public Shareholder exercises its redemption rights in full, then it will be electing to exchange its Public Shares for cash and will no longer own Public Shares. See “Extraordinary General Meeting of Cayson — Redemption Rights” in the accompanying proxy statement/prospectus for a detailed description of the procedures to be followed if you wish to redeem your Public Shares for cash.

The Sponsors and Cayson’s officers and directors have agreed to, among other things, vote in favor of the Business Combination and the other proposals to be presented at the Meeting and have waived their redemption rights in connection with the consummation of the Business Combination, in each case with respect to any Cayson Ordinary Shares held by them, subject to applicable securities laws. Such persons waived their redemption rights in order to induce Cayson and EarlyBirdCapital, Inc., the representative of the underwriters in Cayson’s IPO (“EBC”), to enter into the underwriting agreement for the IPO. In addition, EBC has waived its redemption rights in connection with the consummation of the Business Combination with respect to the 100,000 EBC Founder Shares held by it. No person was paid any consideration in exchange for these waivers. For the avoidance of doubt, the Founder Shares, the EBC Founder Shares and the Private Shares will be excluded from the pro rata calculation used to determine the per-share redemption price.

Cayson is providing the accompanying proxy statement/prospectus and proxy card to Cayson shareholders in connection with the solicitation of proxies to be voted at the Meeting and at any adjournments of the Meeting. Information about the Meeting, the Business Combination and other related matters to be considered by Cayson shareholders at the Meeting is included in the accompanying proxy statement/prospectus. Whether or not you plan to attend the Meeting, all Cayson shareholders are urged to read the accompanying proxy statement/prospectus, including the annexes and other documents referred to therein, carefully and in their entirety. You should also carefully consider the risk factors described in “Risk Factors” beginning on page 67 of the accompanying proxy statement/prospectus.

After careful consideration, the board of directors of Cayson (the “Cayson Board”) has unanimously approved the Business Combination, determined that the Business Combination is advisable and in the best interests of Cayson and its shareholders, and recommended that shareholders vote “FOR” the Business Combination Proposal and “FOR” all other proposals to be presented to the Cayson shareholders at the Meeting. When you consider the recommendation of these proposals by the Cayson Board, you should keep in mind that Cayson’s officers and directors, as well as Mango’s officers and directors, have interests in the Business Combination that may conflict with your interests as a shareholder. See the section entitled “Proposal No. 1: The Business Combination Proposal — Interests of Cayson’s Directors and Executive Officers in the Business Combination” in the accompanying proxy statement/prospectus for a further discussion of these considerations.

Cayson received an opinion from King Kee Appraisal and Advisory Limited (“King Kee”) evaluating the fairness, from a financial point of view, to the Public Shareholders of the consideration to be paid to the Cayson shareholders in the Merger. For more information, please see the section entitled “Shareholder Proposal No. 1: The Business Combination Proposal — Opinion of King Kee, Fairness Opinion Provider.”

The approval of the Merger Proposal requires a special resolution under Cayman Islands law, being a resolution passed by a majority of at least two-thirds (2/3) of the votes cast by or on behalf of the holders of shares of Cayson who are entitled to vote at the Meeting. The approval of each of the Business Combination Proposal, the Nasdaq Proposal, the Non-Binding Governance Proposals (which are comprised of non-binding advisory proposals) and the Adjournment Proposal requires an ordinary resolution, being a resolution passed by a simple majority of the votes cast by, or on behalf of, the holders of shares of Cayson entitled to vote thereon.

Your vote is very important. Whether or not you plan to attend the Meeting, please vote as soon as possible by following the instructions in the accompanying proxy statement/prospectus to make sure that your shares are represented at the Meeting. If you hold your shares in “street name” through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that your shares are represented and voted at the Meeting. In most cases you may vote by telephone or over the Internet as instructed. The Merger will be consummated only if the Condition Precedent Proposals are approved at the Meeting. The approval of each of the Condition Precedent Proposals are a cross-conditioned on the approval of the other. The approval of the Nasdaq Proposal and the Non-Binding Governance Proposals also are conditioned on the approval of the Condition Precedent Proposals. None of the proposals are conditioned on the approval of the Nasdaq Proposal or the Non-Binding Governance Proposals. However, the Business Combination will not be consummated unless such proposals are approved or the corresponding condition in the Business Combination Agreement is waived by the parties to such agreement. If the Adjournment Proposal is presented, the other proposals will not be presented. The Non-Binding Governance Proposals are constituted of non-binding advisory proposals.

If you sign, date and return your proxy card without indicating how you wish to vote, your shares will be counted towards the quorum requirement and will be voted “FOR” each of the proposals presented at the Meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the Meeting in person via live webcast and teleconference, the effect will be, among other things, that your shares will not be counted for purposes of determining whether a quorum is present at the Meeting and will not be voted. An abstention will be counted towards the quorum requirement but will not count as a vote cast at the Meeting. We expect that all proposals being voted on at the Meeting will be considered non-routine under the rules of the NYSE, which generally controls the ability of brokers to vote or not vote shares held in street name on certain matters, and therefore we do not expect any broker non-votes to be submitted and broker non-votes will therefore have no impact on quorum or the vote. If you are a shareholder entitled to attend the Meeting and you wish to attend and vote in person via live webcast and teleconference, you may withdraw your proxy and vote in person via live webcast and teleconference.

Pro Forma Ownership

It is anticipated that, immediately following the Business Combination, the ownership of Mango will be as set forth in the table below. Though the Earnout Shares will not be paid at the Closing, the information in the table below assumes the Earnout Shares have been paid, in order to present the maximum potential dilution to the shareholders of Cayson (the “Cayson shareholders”) from the Business Combination.

Sponsor Compensation

Cayson Holding and Yawei Cao are “SPAC sponsors” as such term is defined in the SEC’s rules governing special purpose acquisition companies, such as Cayson. The Sponsors and their affiliates, including the details of their involvement with Cayson, background about their key personnel and the involvement of such key personnel with other special purpose acquisition companies, are described further in the section of this proxy statement/prospectus titled “Information about Cayson — Sponsors and their Affiliates.”

The following table presents information regarding compensation of the Sponsors and their affiliates, including securities and promissory notes issued to the Sponsors, as required by the SEC’s rules governing special purpose acquisition companies:

On May 29, 2024, Cayson Holding acquired an aggregate of 1,725,000 Founder Shares for an aggregate purchase price of $25,000, or approximately $0.014 per share. Thereafter, it transferred an aggregate of 862,500 Founder Shares to Yawei Cao, Cayson’s Chairman of the Board and Chief Executive Officer, for the same per share purchase price originally paid for such shares, or approximately $0.014 per share. Subsequently, in Cayson’s IPO and simultaneous private placement, Mr. Cao and TenX, an affiliate of Cayson Holding, purchased 230,000 Private Units (19,780 by Mr. Cao and 210,220 by TenX). Each Private Unit is comprised of one Private Share and one Private Right, each Private Right to be converted automatically into 1/10 of one Cayson Ordinary Share upon consummation by Cayson of an initial business combination. Mr. Cao and TenX paid a purchase price of $10.00 per Private Unit, which is identical to the purchase price paid for the Public Units sold in the IPO, and the Private Units are substantially similar to the Public Units sold in the IPO. On October 15, 2024, Cayson’s underwriters elected to terminate their over-allotment option from the IPO and as a result an aggregate of 225,000 Founder Shares were forfeited by the Sponsors and cancelled (112,500 by each of Cayson Holding and Mr. Cao).

Accordingly, as of the closing of the IPO, the Sponsors collectively paid an aggregate of $2,325,000 ($12,500 by Cayson Holding, $210,300 by Mr. Cao and $2,102,200 by TenX) for 1,730,000 Cayson Ordinary Shares (750,000 shares for Cayson Holding, or approximately $0.01 per share, 769,780 shares for Mr. Cao, or approximately $0.27 per share, and $2,102,200 for TenX, or approximately $10.00 per share).

The IPO resulted in the sale and issuance of 6,000,000 Cayson Ordinary Shares for $60,000,000 before expenses, assuming the entire purchase price of the Cayson Units sold in the IPO is allocated to the Cayson Ordinary Shares included in such units, and none of the purchase price is allocated to the Cayson Rights included in such units. The entire purchase price has been allocated to the Cayson Ordinary Shares for the purposes of this discussion in order to show the maximum dilution caused by the investment and holdings by the Sponsors and their affiliates as of the closing of the IPO. In accordance with the above, as of immediately following the IPO, counting the investment and holdings by the Sponsors and their affiliates and those by the Public Shareholders, Cayson had a net tangible book value of $58,617,237 and 8,055,000 Cayson Ordinary Shares outstanding, for a net tangible book value per share of approximately $7.28. As such, the holdings and investment by the Sponsors and their affiliates resulted in dilution of approximately $2.72 per Cayson Ordinary Share to the Public Shareholders.

Additionally, as of date of this filing, a total of $110,000 of service fees have been paid by Cayson for services rendered by Cayson Holding pursuant to an administrative services agreement between Cayson and Cayson Holding, and a total of $150,000 of service fees have been paid by Cayson for services rendered by TenX pursuant to a consulting and advisory agreement between Cayson and TenX, for a total of $260,000 of paid and accrued compensation to the Sponsors and their affiliates.

Furthermore, if the Sponsors or their affiliates were to loan any amounts to Cayson and/or incur any fees or out-of-pocket expenses on Cayson’s behalf, the total sum of such loans, fees and out-of-pocket expenses would be repayable on or after the Closing and/or in certain cases convertible into additional units. If any such amounts were loaned or incurred and Cayson fails to complete an initial business combination before its deadline pursuant to Cayson’s M&A, as may be amended to extend such date, such amounts would be forfeited except to the extent there are any out of trust funds available to be used to repay such amounts. As of the date of the accompanying proxy statement/prospectus, there are no amounts outstanding under any loans payable to the Sponsors or their affiliates and no fees due or out-of-pocket expenses to be repaid by Cayson to the Sponsors or their affiliates.

Given the holdings of the Sponsors and their affiliates, as of the consummation of the Business Combination, they will collectively hold 1,753,000 Mango Ordinary Shares. Cayson Holding will hold 750,000 Mango Ordinary Shares, Mr. Cao will hold 771,758 Mango Ordinary Shares (including 1,978 Mango Ordinary Shares issued in respect of 19,780 Private Rights included in the Private Units), and TenX will hold 231,242 Mango Ordinary Shares (including 21,022 Mango Ordinary Shares issued in respect of 210,220 Private Rights included in the Private Units). The Mango Ordinary Shares to be held by the Sponsors following the Business Combination will be identical to the Mango Ordinary Shares to be held by Cayson’s Public Shareholders in every respect. Because only the 23,000 Mango Ordinary Shares to be issued in respect of the Private Rights held by Mr. Cao and TenX will be new issuances, only those securities could result in additional material dilution to the Public Shareholders, and because the Public Shareholders will also be issued Mango Ordinary Shares in respect of their Public Rights, in the same proportion or greater to Mr. Cao and TenX, since Public Shareholders who redeem their Public Shares will still keep their Public Rights and receive Mango Ordinary Shares in respect of such rights, the issuance to Mr. Cao and TenX of Mango Ordinary Shares in respect of its Private Rights could reasonably be seen as not causing any additional substantial dilution to the Public Shareholders.

* * * * * * * * * *

If you have any questions or need assistance voting your ordinary shares, please contact [●], Cayson’s proxy solicitor, by calling toll-free (within the U.S. or Canada) at [●], or for banks and brokers, by calling collect at [●], or by emailing [●].

On behalf of the Cayson Board, we would like to thank you for your support and look forward to the successful completion of the Business Combination.

NEITHER THE SEC NOR ANY STATE SECURITIES REGULATORY AGENCY HAS APPROVED OR DISAPPROVED THE TRANSACTIONS DESCRIBED IN THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS, PASSED UPON THE MERITS OR FAIRNESS OF THE BUSINESS COMBINATION OR RELATED TRANSACTIONS OR PASSED UPON THE ADEQUACY OR ACCURACY OF THE DISCLOSURE IN THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY CONSTITUTES A CRIMINAL OFFENSE.

Neither Cayson nor Mango is licensed to conduct investment business in the Cayman Islands by the Cayman Islands Monetary Authority and the accompanying proxy statement/prospectus does not constitute an offer to members of the public of their share, whether by way of sale or subscription, in the Cayman Islands. The share of Cayson and Mango have not been offered or sold, will not be offered or sold and no invitation to subscribe for the ordinary shares of Cayson and Mango will be made, directly or indirectly, to members of the public in the Cayman Islands.

The accompanying proxy statement/prospectus is dated [●], 2026 and is first being mailed to shareholders on or about [●], 2026.

ABOUT THIS PROXY STATEMENT/PROSPECTUS

This document, which forms part of a registration statement on Form F-4 (File No. 333-[●]) filed by Mango with the SEC constitutes a prospectus of Mango under Section 5 of the Securities Act with respect to certain securities of Mango to be issued in connection with the Business Combination described below. This document also constitutes a notice of meeting and a proxy statement of Cayson under Section 14(a) of the Exchange Act, for an extraordinary general meeting of shareholders to be held in connection with the Business Combination and at which the Cayson shareholders will be asked to consider and vote upon a proposal to adopt the Business Combination Agreement and approve the Business Combination, among other matters.

ADDITIONAL INFORMATION

You may request copies of this proxy statement/prospectus and any other publicly available information concerning Cayson, without charge: from Cayson, by writing to Cayson Acquisition Corp, 205 West 37th Street, New York, New York 10018, or by calling (203) 998-5540, or from [●], Cayson’s proxy solicitor, by calling [●] (toll-free within the U.S. or Canada), or for banks and brokers, by calling [●] (collect), or by sending an email to [●]. You may also obtain copies of this proxy statement/prospectus and other documents publicly filed by Cayson from the SEC, through the SEC website at http://www.sec.gov.

In order for a Cayson shareholder to receive timely delivery of the applicable documents in advance of the Meeting to be held on [●], 2026, such shareholder must request the information no later than five (5) business days prior to the date of the meeting, or by [●], 2026.

CAYSON ACQUISITION CORP
205 West 37th Steet
New York, New York 10018

NOTICE OF EXTRAORDINARY GENERALMEETING OF SHAREHOLDERS
TO BE HELD ON [●], 2026

TO THE SHAREHOLDERS OF CAYSON ACQUISITION CORP:

NOTICE IS HEREBY GIVEN that an extraordinary general meeting (the “Meeting”) of Cayson Acquisition Corp, a Cayman Islands exempted company, company number 410337 (“Cayson”), will be held at [●], Eastern Time, on [●], 2026, virtually via live webcast at [●] and via teleconference at [●] (U.S. toll free) or [●] (international toll free) (in each case using participant code [●]), or at such other time and place to which the Meeting may be adjourned. Shareholders of Cayson (“Cayson shareholders”) may attend the Meeting by visiting the live webcast website, where they will be able to listen to the Meeting live and vote during the Meeting. We are pleased to utilize virtual shareholder meeting technology to provide ready access and cost savings for Cayson shareholders and Cayson. See “Frequently Used Terms” in the accompanying proxy statement/prospectus for definitions of certain terms used in this notice.

You are cordially invited to attend the Meeting, which will be held to consider and vote, and if thought fit, pass and approve, the following resolutions:

The approval of each of Proposal Nos. 1 and 2 (the “Condition Precedent Proposals”) is cross-conditioned on the approval of the other. Approval of Proposal Nos. 3 and 4 also are conditioned upon the approval of the Condition Precedent Proposals. None of the proposals are conditioned on approval of Proposal Nos. 3 or 4. However, the business combination for which the Business Combination Agreement provides (the “Business Combination”) will not be consummated unless all the proposals are approved or the corresponding condition in the Business Combination Agreement is waived by the parties to such agreement. If Proposal No. 5 is presented, the other proposals will not be presented. Proposal No. 4 is constituted of non-binding advisory proposals. Each of these proposals is more fully described in the accompanying proxy statement/prospectus, which each shareholder is encouraged to read carefully and in its entirety.

Only holders of record of Cayson Ordinary Shares at the close of business on [●], 2026 are entitled to notice of and to vote and have their votes counted at the Meeting and any adjournment of the Meeting.

The accompanying proxy statement/prospectus and accompanying proxy card are being provided to Cayson shareholders in connection with the solicitation of proxies to be voted at the Meeting and at any adjournment of the Meeting. Whether or not you plan to attend the Meeting, all Cayson shareholders are urged to read this proxy statement/prospectus, including the annexes and the documents referred to herein, carefully and in their entirety. You should also carefully consider the risk factors described in “Risk Factors” beginning on page 67 of the accompanying proxy statement/prospectus.

 After careful consideration, the Cayson Board has unanimously approved the Business Combination, determined that the Business Combination is advisable and in the best interests of Cayson and its shareholders, and recommended that shareholders vote “FOR” the adoption of the Business Combination Proposal and “FOR” all other proposals to be presented to Cayson shareholders at the Meeting. When you consider the recommendation of these proposals by the Cayson Board, you should keep in mind that Cayson’s officers and directors have interests therein that may conflict with your interests as a shareholder. See the section entitled “Proposal No. 1: The Business Combination Proposal — Conflicts of Interest of the Sponsors and Cayson’s Officers and Directors” in the accompanying proxy statement/prospectus for a further discussion of these considerations.

Pursuant to Cayson’s M&A, the holders of the Public Shares, excluding Cayson Holding LP (“Cayson Holding”) and Yawei Cao (together with Cayson Holding, the “Sponsors”) and Cayson’s officers and directors, may elect to have all or a portion of such shareholder’s Public Shares redeemed for cash if the Business Combination is consummated, provided that no such shareholder acting together with any affiliate of his or any other person with whom he is acting in concert or as a partnership, syndicate, or other group for the purposes of acquiring, holding, or disposing of shares of Cayson may exercise this redemption right with respect to more than 15% of the Public Shares without the Cayson’s prior consent. You will be entitled to receive cash for any Public Shares to be redeemed only if you:

Public Shareholders must complete the procedures for electing to redeem their Public Shares in the manner described above prior to 5:00 p.m., Eastern Time, on [●], 2026 (two (2) business days before the Meeting) in order for their shares to be redeemed. Public Shareholders may elect to redeem their Public Shares whether they vote “for” or “against” or do not vote at all on the Business Combination Proposal or the other proposals to be voted upon at the Meeting.

If you hold Cayson Ordinary Shares through Cayson Units, you must elect to separate your Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights prior to exercising your redemption rights with respect to the Public Shares. If you hold your Cayson Units in an account at a brokerage firm or bank, you must notify your broker or bank that you elect to separate the Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights, or if you hold Cayson Units registered in your own name, you must contact Continental, Cayson’s transfer agent, directly and instruct it to do so.

Notwithstanding the foregoing, no holder of Public Shares, acting individually or together with any affiliate of such holder or any other person with whom such holder is acting in concert or as a partnership, syndicate, or other group (as defined in Section 13(d)(3) of the Exchange Act) for the purposes of acquiring, holding, or disposing of Cayson Ordinary Shares, may exercise this redemption right with respect to more than 15% of the Public Shares without Cayson’s prior consent. Accordingly, all Public Shares in excess of that 15% limit will not be redeemed for cash.

If the Business Combination is not consummated, the Public Shares will be returned to their respective holders, brokers or banks. If the Business Combination is consummated, and if a Public Shareholder properly exercises its right to redeem all or a portion of the Public Shares that it holds and timely delivers its shares to Continental, Cayson will redeem such Public Shares for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account established at the consummation of Cayson’s Initial Public Offering (the “trust account”), including any interest earned on the funds held in the trust account and not previously released to Cayson to pay its taxes, divided by the number of then outstanding Public Shares, calculated as of two (2) business days prior to the consummation of the Business Combination. For illustrative purposes, as of [__], 2026, this would have amounted to approximately $[__] per issued and outstanding Public Shares. If a Public Shareholder exercises its redemption rights in full, then it will be electing to exchange its Public Shares for cash and will no longer own Public Shares. See “Extraordinary General Meeting of Cayson  — Redemption Rights” in the accompanying proxy statement/prospectus for a detailed description of the procedures to be followed if you wish to redeem your Public Shares for cash.

The Sponsors and Cayson’s officers and directors have agreed to, among other things, vote in favor of the Business Combination and the other proposals to be presented at the Meeting and have waived their redemption rights in connection with the consummation of the Business Combination, in each case with respect to any Cayson Ordinary Shares held by them, subject to applicable securities laws. Such persons waived their redemption rights in order to induce Cayson and EarlyBirdCapital, Inc., the representative of the underwriters in Cayson’s IPO (“EBC”), to enter into the underwriting agreement for the IPO. In addition, EBC has waived its redemption rights in connection with the consummation of the Business Combination with respect to the 100,000 EBC Founder Shares held by it. No person was paid any consideration in exchange for these waivers. For the avoidance of doubt, the Founder Shares, the EBC Founder Shares and the Private Shares will be excluded from the pro rata calculation used to determine the per-share redemption price.

The approval of the Merger Proposal requires a special resolution under Cayman Islands law, being a resolution passed by a majority of at least two-thirds (2/3) of the votes cast by or on behalf of the holders of shares of Cayson who are entitled to vote at the Meeting. The approval of each of the Business Combination Proposal, the Nasdaq Proposal, the Non-Binding Governance Proposals (which are comprised of non-binding advisory proposals) and the Adjournment Proposal requires an ordinary resolution, being a resolution passed by a simple majority of the votes cast by or on behalf of the shareholders entitled to vote thereon.

Your vote is very important. Whether or not you plan to attend the Meeting, please vote as soon as possible by following the instructions in the accompanying proxy statement/prospectus to make sure that your shares are represented at the Meeting. If you hold your shares in “street name” through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that your shares are represented and voted at the Meeting. In most cases you may vote by telephone or over the Internet as instructed. The Merger will be consummated only if the Condition Precedent Proposals are approved at the Meeting. The approval of each of the Condition Precedent Proposals are a cross-conditioned on the approval of the other. The approval of the Nasdaq Proposal and the Non-Binding Governance Proposals also are conditioned on the approval of the Condition Precedent Proposals. None of the proposals are conditioned on the approval of the Nasdaq Proposal or the Non-Binding Governance Proposals. However, the Business Combination will not be consummated unless such proposals are approved or the corresponding condition in the Business Combination Agreement is waived by the parties to such agreement. If the Adjournment Proposal is presented, the other proposals will not be presented. The Non-Binding Governance Proposals are constituted of non-binding advisory proposals.

If you sign, date and return your proxy card without indicating how you wish to vote, your shares will be counted towards the quorum requirement and will be voted “FOR” each of the proposals presented at the Meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the Meeting in person via live webcast and teleconference, the effect will be, among other things, that your shares will not be counted for purposes of determining whether a quorum is present at the Meeting and will not be voted. An abstention will be counted towards the quorum requirement but will not count as a vote cast at the Meeting. We expect that all proposals being voted on at the Meeting will be considered non-routine under the rules of the NYSE, which generally controls the ability of brokers to vote or not vote shares held in street name on certain matters, and therefore we do not expect any broker non-votes to be submitted and broker non-votes will therefore have no impact on quorum or the vote. If you are a shareholder entitled to attend the Meeting and you wish to attend and vote in person via live webcast and teleconference, you may withdraw your proxy and vote either in person via live webcast and teleconference.

Your attention is directed to the remainder of the accompanying proxy statement/prospectus following this notice (including the annexes and other documents referred to herein) for a more complete description of the proposed Business Combination and related transactions and each of the proposals. You are encouraged to read the accompanying proxy statement/prospectus carefully and in its entirety, including the annexes and other documents referred to herein. If you have any questions or need assistance voting your ordinary shares, please contact [●], Cayson’s proxy solicitor, by calling toll-free (within the U.S. or Canada) at [●], or for banks and brokers, by calling collect at [●], or by emailing [●].

Thank you for your participation. We look forward to your continued support.

By Order of the Board of Directors of Cayson Acquisition Corp, dated [●], 2026.

TABLE OF CONTENTS

FREQUENTLY USED TERMS

Unless otherwise stated in this proxy statement/prospectus or the context otherwise requires:

TRADEMARKS

This proxy statement/prospectus also contains trademarks, service marks, copyrights and trade names of other companies, which are the property of their respective owners. We do not intend our use or display of other companies’ trademarks, copyrights or trade names to imply a relationship with, or endorsement or sponsorship of us by, any other companies. Solely for convenience, Mango’s and Cayson’s trademarks and trade names referred to in this proxy statement/prospectus may appear without the ® or ™ symbols, but such references are not intended to indicate, in any way, that Mango and Cayson will not assert, to the fullest extent under applicable law, their respective rights or the right of the applicable licensor to these trademarks and trade names.

MARKET AND INDUSTRY DATA

This proxy statement/prospectus includes industry position and industry data and forecasts that Mango and Cayson obtained or derived from internal company reports, independent third-party publications and other industry data. Some data are also based on good faith estimates, which are derived from internal company analyses or review of internal company reports as well as the independent sources referred to above.

Statements as to industry position are based on market data currently available. While neither Mango nor Cayson are aware of any misstatements regarding the industry data presented herein, these estimates involve risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” in this proxy statement/prospectus.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus contains forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. These forward-looking statements include, among other things, statements about the parties’ ability to close the Business Combination, the timing of the Closing, the anticipated benefits of the Business Combination, the financial conditions, results of operations, earnings outlook and prospects of Mango, Cayson and New Mango and the period following the consummation of the Business Combination. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. Forward-looking statements are typically identified by words such as “plan,” “believe,” “expect,” “anticipate,” “intend,” “outlook,” “estimate,” “forecast,” “project,” “continue,” “could,” “may,” “might,” “possible,” “potential,” “predict,” “should,” “would,” “will,” “seek,” “target,” and other similar words and expressions, but the absence of these words does not mean that a statement is not forward-looking.

The forward-looking statements are based on information available as of the date of this proxy statement/prospectus and on the current expectations, forecasts, assumptions and judgments of the management of Mango and Cayson and involve a number of risks and uncertainties. These forward-looking statements are inherently subject to changes in circumstances and their potential effects and speak only as of the date of such statements. There can be no assurance that future developments will be those that have been anticipated. The risks and uncertainties that may cause actual results or performance to be materially different from those expressed, contemplated or implied by these forward-looking statements include, but are not limited to, those factors described in “Risk Factors,” those discussed and identified in public filings made with the SEC by Cayson, and the following:

Should one or more of these risks or uncertainties materialize, or should any of the expectations, forecasts, assumptions or judgments made by the management of Mango or Cayson otherwise prove incorrect, actual results may vary in material respects from those projected in or contemplated by these forward-looking statements.

All subsequent written and oral forward-looking statements concerning the Business Combination or other matters addressed in this proxy statement/prospectus and attributable to Mango or Cayson or any person acting on their behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this proxy statement/prospectus. Except to the extent required by applicable law or regulation, neither Mango nor Cayson undertakes any obligation to update these forward-looking statements to reflect events or circumstances after the date of this proxy statement/prospectus or to reflect the occurrence of unanticipated events.

QUESTIONS AND ANSWERS ABOUT THE CAYSON SHAREHOLDER PROPOSALS

The questions and answers below highlight only selected information from this proxy statement/prospectus and only briefly address some commonly asked questions about the proposals to be presented at the Meeting, including with respect to the Business Combination. The following questions and answers do not include all the information that is important to the Cayson shareholders. Cayson urges the Cayson shareholders to read this proxy statement/prospectus, including the annexes and the other documents referred to herein, carefully and in their entirety to fully understand the Business Combination and the voting procedures for the Meeting.

Q: Why am I receiving this proxy statement/prospectus?

A: You are receiving these materials because you were a shareholder of record or a beneficial holder of Cayson on the record date. Cayson and Mango have agreed to undertake the Business Combination through a series of transactions to be completed in accordance with the terms and conditions of the Business Combination Agreement and the other Transaction Documents (as defined in the Business Combination Agreement). A copy of the Business Combination Agreement is attached as Annex A. Cayson shareholders are being asked to consider and vote upon a proposal to approve the Business Combination, along with a number of other proposals. See the section entitled “Summary of the Proxy Statement/Prospectus” for more detail.

THE VOTE OF CAYSON SHAREHOLDERS IS IMPORTANT. CAYSON SHAREHOLDERS ARE ENCOURAGED TO VOTE AS SOON AS POSSIBLE AFTER CAREFULLY REVIEWING THIS PROXY STATEMENT/ PROSPECTUS IN ITS ENTIRETY, INCLUDING THE ANNEXES.

Q: What proposals are shareholders of Cayson being asked to vote upon?

A: At the Meeting, Cayson is asking holders of Cayson Ordinary Shares to consider and vote upon the following proposals:

See “Proposal No. 1: The Business Combination Proposal,” “Proposal No. 2: The Merger Proposal,” “Proposal No. 3: The NTA Proposal,” “Proposal No. 4: The Nasdaq Proposal,” “Proposal No. 5: The Non-Binding Governance Proposals” and “Proposal No. 6: The Adjournment Proposal.”

Cayson will hold the Meeting to consider and vote upon these proposals. This proxy statement/prospectus contains important information about the Business Combination and the other matters to be acted upon at the Meeting. The Cayson shareholders should read it carefully.

After careful consideration, the Cayson Board has determined that the Business Combination Proposal, the Merger Proposal, the Nasdaq Proposal, the Non-Binding Governance Proposals and the Adjournment Proposal are in the best interests of Cayson and its shareholders and unanimously recommends that you vote or give instruction to vote “FOR” each of those proposals. If Cayson shareholders do not approve each of the Condition Precedent Proposals, then the Business Combination Agreement may be terminated and the Business Combination may not be consummated.

The existence of financial and personal interests of one or more of Cayson’s directors may result in a conflict of interest on the part of such directors between what he, she or they may believe is in the best interests of Cayson and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, Cayson’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. See the section entitled “Proposal No. 1: The Business Combination Proposal — Conflicts of Interest of the Sponsors and Cayson’s Officers and Directors” for a further discussion of these considerations.

Q: Why is Cayson proposing the Business Combination?

A: Cayson was incorporated to effect a merger, share exchange, asset acquisition, share purchase, reorganization, or similar business combination, with one or more businesses or entities.

Based on Cayson’s due diligence investigations of Mango, the management of Mango and the industry in which it operates, including the financial and other information provided by Mango in the course of these due diligence investigations, the Cayson Board believes that the business combination with Mango is in the best interests of Cayson and its shareholders and presents an opportunity to increase shareholder value. However, there can be no assurance of this. Although the Cayson Board believes that the business combination with Mango presents an attractive business combination opportunity and is in the best interests of Cayson and its shareholders, the Cayson Board did consider certain potentially material negative factors in arriving at that conclusion, including, among others, the potential inability of Mango to achieve its business plan, the risk that a significant number of Public Shareholders elect to redeem their Public Shares, the impact of the review of the Business Combination by regulatory agencies, such as the SFC, the risk that the conditions to closing may not be satisfied and the risk that the potential benefits of the Business Combination may not be achieved. The Cayson Board also considered certain key business risks, including the regulatory risks associated with Mango’s operations in Hong Kong, Mango’s limited public company experience, client concentration and revenue volatility, uncertainty regarding the PIPE Financing, and the potential impact of high redemption levels on dilution and satisfaction of the minimum net tangible asset requirement. For additional information, see the section entitled “Proposal No. 1: The Business Combination Proposal — Recommendation of the Cayson Board and Reasons for the Business Combination,” as well as the risks described in the section entitled “Risk Factors.”

Under Cayson’s M&A and the Cayman Companies Act, Cayson is required to obtain the approval of the Cayson shareholders in order to complete the Business Combination.

Q: How will the Business Combination be accomplished?

A: In accordance with the Business Combination Agreement, the Business Combination will be accomplished by way of the following transaction steps:

As a result of the Business Combination, Cayson will become a wholly owned subsidiary of Mango, the security holders of Cayson immediately prior to the Effective Time will become security holders of Mango, and Mango will become a public holding company conducting the business of Mango Financial.

The Business Combination values Mango at $140,000,000, based on 14,000,000 Mango Ordinary Shares to be outstanding immediately prior to the Business Combination and an assumed value of $10.00 per Mango Ordinary Share.

Q: What will the Cayson shareholders receive in exchange for their Cayson Securities?

A: As described above, at the Effective Time of the Merger, each outstanding Cayson Ordinary Share, other than shares owned by Cayson in treasury and dissenting shares, including the Cayson Ordinary Shares that are components of the Cayson Units and that are issuable in respect of the Cayson Rights, will be canceled and automatically converted into one Mango Ordinary Share.

Mango intends to apply to list the Mango Ordinary Shares on Nasdaq. It is a condition of the consummation of the Business Combination that the listing of the Mango Ordinary Shares has been approved by Nasdaq, subject only to official notice of issuance thereof, but there can be no assurance such listing condition will be met or that Mango will obtain such approval from Nasdaq. If such listing condition is not met or if such approval is not obtained, the Business Combination still may be consummated, if the corresponding condition set forth in the Business Combination Agreement is waived by the parties.

Many of the principal attributes of Cayson Ordinary Shares and Mango Ordinary Shares will be similar. However, there are material differences between Cayson’s M&A and New Mango’s M&A, as such will be in effect from and after the consummation of the Business Combination.

For further details, see “Proposal No. 1: The Business Combination Proposal — Business Combination Agreement — Business Combination Consideration” and “Comparison of Shareholders’ Rights.”

Q: What are the material U.S. federal income tax consequences to Cayson shareholders resulting from the Business Combination?

A: It is intended that the Business Combination qualify as a “reorganization” within the meaning of Section 368(a) of the Code, with respect to U.S. Holders of Cayson Ordinary Shares. However, there are significant factual and legal uncertainties as to whether the Business Combination will qualify as a reorganization within the meaning of Section 368(a) of the Code. If any requirement for Section 368(a) of the Code is not met, then a U.S. Holder of Cayson Ordinary Shares would generally recognize gain or loss in an amount equal to the difference, if any, between the fair value of Mango Ordinary Shares received in the Business Combination, over such U.S. Holder’s aggregate tax basis in the corresponding Cayson Ordinary Shares surrendered by such U.S. Holder in the Business Combination. Even if the Business Combination otherwise qualifies as a “reorganization” within the meaning of Section 368(a) of the Code, U.S. Holders may be required to recognize gain (but not loss) on account of the application of the Passive Foreign Investment Company (“PFIC”) rules. For more detail, see below under “Proposal No. 1: The Business Combination Proposal —  Material U.S. Federal Income Tax Considerations — U.S. Federal Income Tax Considerations of the Business Combination.”

U.S. Holders of Cayson Securities should consult their tax advisors to determine the tax consequences if the Business Combination does not qualify as a “reorganization” within the meaning of Section 368(a) of the Code and for the application of the PFIC rules to their specific situation in connection with the Business Combination.

Q: Do Cayson and Mango expect to obtain new financing in connection with the Business Combination?

A: Yes. Mango and Cayson have agreed to use their reasonable best efforts to enter into definitive agreements for the sale of at least $5,000,000 of equity securities of Cayson in the PIPE Financing to be consummated immediately prior to the Closing. Mango and Cayson expect that each PIPE Investor will also enter into a customary registration rights agreement. There are currently no commitments for such PIPE Financing.

Q: Do I have redemption rights?

A: If you are a holder of Public Shares, you have the right to request that we redeem all or a portion of your Public Shares for cash, provided that you follow the procedures and deadlines described elsewhere in this proxy statement/prospectus. Public Shareholders may elect to redeem all or a portion of the Public Shares held by them regardless of whether they vote for or against the Business Combination Proposal and the Merger Proposal or if they do not vote on such proposals at all. If you wish to exercise your redemption rights, please see the answer to the question: “How do I exercise my redemption rights?”

Notwithstanding the foregoing, a Public Shareholder, together with any affiliate of such Public Shareholder or any other person with whom such Public Shareholder is acting in concert or as a partnership, syndicate, or other group for the purposes of acquiring, holding, or disposing of Cayson Ordinary Shares, will not, without Cayson’s prior consent, redeem its Public Shares with respect to more than an aggregate of 15% of the Public Shares included in the Cayson Units sold in Cayson’s IPO. Accordingly, if a Public Shareholder, alone or acting in concert or as a group, seeks to redeem more than 15% of the Public Shares, then any such shares in excess of that 15% limit would not be redeemed for cash or at all.

If you exercise your redemption rights, such exercise will not result in the loss of any Cayson Rights that you may hold. Upon the Closing, each of your Cayson Rights will convert into 1/10 of one Cayson Ordinary Share regardless of whether you have chosen to redeem their Public Shares (which, in turn, will be automatically converted Mango Ordinary Shares upon the Effective Time of the Merger). However, with fewer Public Shares and potentially fewer Public Shareholders, Mango may not meet the listing standards for Nasdaq.

The Sponsors and the other Insiders have waived their redemption rights in connection with the consummation of the Business Combination, with respect to any Cayson Ordinary Shares held by them. EBC also has waived its redemptions rights in connection with the consummation of the Business Combination, with respect to the EBC Founder Shares. No person was paid any consideration in exchange for these waivers. For the avoidance of doubt, the Founder Shares, EBC Founder Shares and Private Shares will be excluded from the pro rata calculation used to determine the per-share redemption price.

Q: How do I exercise my redemption rights?

A: If you are a Public Shareholder and wish to exercise your right to redeem your Public Shares for cash, you must:

You must complete the procedures for electing to redeem your Public Shares in the manner described above prior to 5:00 p.m., Eastern Time, on [●] (two (2) business days before the Meeting) in order for your shares to be redeemed. You may elect to redeem your Public Shares whether they vote “for” or “against” or do not vote at all on the Business Combination Proposal or the other proposals to be voted upon at the Meeting.

If you hold Cayson Ordinary Shares through Cayson Units, you must elect to separate your Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights prior to exercising your redemption rights with respect to the Public Shares. If you hold your Cayson Units in an account at a brokerage firm or bank, you must notify your broker or bank that you elect to separate the Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights, or if you hold Cayson Units registered in your own name, you must contact Continental, Cayson’s transfer agent, directly and instruct it to do so. The contact information for Continental is listed under the question “Who can help answer my questions?” below.

If the Business Combination is not consummated, your Public Shares will be returned to you or your broker or bank, as applicable. If the Business Combination is consummated, and if you properly exercise your right to redeem all or a portion of the Public Shares that you hold and timely deliver your shares to Continental, Cayson will redeem such Public Shares for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, calculated as of two (2) business days prior to the consummation of the Business Combination. For illustrative purposes, as of [__], 2026, after taking into account expected redemptions in connection with the Extension Amendment, this would have amounted to approximately $[__] per issued and outstanding Public Share. However, the proceeds deposited in the trust account could become subject to the claims of Cayson’s creditors, if any, which could have priority over your claim as a Public Shareholder, regardless of whether you vote or, if you do vote, irrespective of if you vote for or against the Business Combination Proposal. Therefore, the per share distribution from the trust account in such a situation may be less than originally expected due to such claims. Whether you vote, and if you do vote, irrespective of how you vote on any proposal, including the Business Combination Proposal, will have no impact on the amount you will receive upon exercise of your redemption rights. It is expected that the funds to be distributed to you if you elect to redeem your Public Shares will be distributed promptly after the consummation of the Business Combination.

If you submit a redemption request to Continental, and later decide prior to the Meeting not to elect redemption, you may request to withdraw the redemption request. You may make such a withdrawal request by contacting Continental.

Any corrected or changed written exercise of redemption rights must be received by Continental prior to the vote taken on the Business Combination Proposal at the Meeting. Your request for redemption will not be honored unless your Public Shares have been delivered (either physically or electronically) to Continental, at least two (2) business days prior to the vote at the Meeting.

Q: If I am a holder of Cayson Units, can I exercise redemption rights with respect to my Cayson Units?

A: No. Although you have redemption rights with respect to the Cayson Ordinary Shares included in the Cayson Units, you have no redemption rights with respect to the Public Units themselves. You must elect to separate your Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights prior to exercising your redemption rights with respect to the Public Shares. If you hold your Cayson Units in an account at a brokerage firm or bank, you must notify your broker or bank that you elect to separate the Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights, or if you hold Cayson Units registered in your own name, you must contact Continental, Cayson’s transfer agent, directly and instruct it to do so. You must cause your Cayson Ordinary Shares to be separated and delivered to Continental by 5:00 p.m., Eastern Time, on [●] (two (2) business days before the Meeting) in order to exercise your redemption rights with respect to your Cayson Ordinary Shares.

Q: Will how I vote affect my ability to exercise redemption rights?

A: No. You may exercise your redemption rights whether you vote your Cayson Ordinary Shares for or against or do not vote at all on the Business Combination Proposal or the other proposals to be voted upon at the Meeting. As a result, the Business Combination can be approved by shareholders who will redeem their shares and no longer remain shareholders.

Q: What are the material U.S. federal income tax consequences of exercising my redemption rights?

A: A U.S. Holder (as defined in “Proposal No. 1: The Business Combination Proposal —Material Federal U.S. Income Tax Consequences”) who exercises its redemption rights will receive cash in exchange for the Cayson Ordinary Shares, and either will be considered for U.S. federal income tax purposes to have made a sale or exchange of the tendered shares, or will be considered for U.S. federal income tax purposes to have received a distribution with respect to such shares that may be treated as: (i) dividend income, (ii) a nontaxable recovery of basis in their investment in the tendered shares, or (iii) gain (but not loss) as if the shares with respect to which the distribution was made had been sold. For additional information, see the section entitled “Proposal No. 1: The Business Combination Proposal —Material Federal U.S. Income Tax Consequences — U.S. Holders Exercising Redemption Rights with Respect to Cayson Ordinary Shares.”

You should consult with your own tax advisor with respect to the U.S. federal income tax consequences of exercising your redemption rights.

Q: How has the announcement of the Business Combination affected the trading price of the Cayson Ordinary Shares?

A: On July 10, 2025, the last trading day before announcement of the execution of the Business Combination Agreement, the reported closing prices on Nasdaq of the Cayson Ordinary Shares, Cayson Units, and Cayson Rights were $10.32, $10.3738 and $0.14, respectively. On [__], 2026, the reported closing prices on Nasdaq of the Cayson Ordinary Shares, Cayson Units and Cayson Rights were $[__], $[__] and $[__], respectively.

Q: What equity stake will Public Shareholders who elect not to redeem their Public Shares hold in New Mango immediately after the completion of the Business Combination?

A: Immediately after completion of the Business Combination, the former Public Shareholders will own a significantly smaller percentage of New Mango than they currently own of Cayson. In addition, because the Public Shareholders may vote in favor of the Business Combination and exercise their redemption rights, the Business Combination may be consummated even though there is a substantial reduction in Public Shares.

The tables below show the anticipated ownership of New Mango upon completion of the Business Combination, along with other potential sources of dilution. The tables show the potential impact of redemptions on the share ownership by non-redeeming shareholders in (i) a no redemption scenario, (ii) 25% redemption scenario, (iii) 75% redemption scenario, and (iv) maximum redemption scenario. The levels of ownership presented in the tables below assume that the 20,000,000 Earnout Shares have been issued but do not give effect to any PIPE Financing. The information in the tables below has been rounded to the nearest whole number or the nearest decimal. Therefore, the sum of the numbers in a column may not conform exactly to the total figure given for that column in the below table. In addition, certain percentages presented in the tables below reflect calculations based upon the underlying information prior to rounding and, accordingly, may not conform exactly to the percentages that would be derived if the relevant calculations were based upon the rounded numbers or may not sum due to rounding.

The former Public Shareholders who do not redeem their Public Shares may experience dilution from several additional sources to varying degrees after the Business Combination. Following the Closing, New Mango may determine, subject to the receipt of any necessary approvals that may be required, to issue more Mango Ordinary Shares or other equity securities of equal or senior rank in connection with privately negotiated transactions following the consummation of the Business Combination. The issuance of Mango Ordinary Shares (or other equity securities of equal or senior rank) could have the following effects for Public Shareholders who elect not to redeem their shares:

Q: What are the possible sources and extent of dilution that Public Shareholders who elect not to redeem their Public Shares will experience in connection with the Business Combination?

A: The following table presents the net tangible book value per share at various redemption levels assuming various sources of material probable dilution (but excluding the effects of the Business Combination transaction itself).

Q: What happens to the funds deposited in the trust account after consummation of the Business Combination?

A: Following the closing of Cayson’s IPO, an amount equal to $60,000,000 of the net proceeds from the IPO and the simultaneous private placement of Private Units was placed in the trust account. As of [__], 2026, funds in the trust account totaled approximately $[__]. Except with respect to interest earned on the funds held in the trust account that may be released to us to pay our tax obligations and in connection with certain amendments to Cayson’s M&A, these proceeds will not be released until the earlier of the completion of an initial business combination and Cayson’s redemption of 100% of the outstanding Public Shares upon its failure to consummate a business combination within the required time period as provided in the Cayson’s M&A or if such date is further extended at a duly called extraordinary general meeting, such later date).

Upon consummation of the Business Combination, the funds deposited in the trust account will be released to pay holders of Public Shares who properly exercise their redemption rights, to pay transaction fees and expenses associated with the Business Combination and for working capital and general corporate purposes of Mango following the Business Combination.

 To extent Public Shareholders exercise their redemption rights, the working capital infusion from the trust account into Mango’s business will be reduced. Under Cayson’s M&A, we are prohibited from redeeming Public Shares in an amount that would cause Cayson’s net tangible assets to be less than $5,000,001 either immediately prior to or upon consummation of its initial business combination and after payment of underwriters’ fees and commissions; however, the required amount may be satisfied through the receipt of assets other than from the trust account, such as proceeds received in the PIPE Financing and the net assets acquired from Mango. Accordingly, the Business Combination may be consummated even where the cash infusion from the trust account is substantially reduced.

Q: What is the expected the cash from the trust account to be received by New Mango in the Business Combination?

A: Following the consummation of the Business Combination, New Mango’s future liquidity position will depend on many factors, including but not limited to (i) the number of Public Shares redeemed in connection with the Business Combination and (ii) the sources of funding available for general corporate and working capital purposes.

Set forth below is a calculation of the estimated net cash to be received by New Mango from the trust account in four redemption scenarios: (a) no redemption scenario, (b) 25% redemption scenario, (c) 75% redemption scenario, and (d) maximum redemption scenario. The calculations assume (i) a redemption price of approximately $10.34 per share, based on cash held in the trust account as of June 30, 2025, and (ii) aggregate transaction expenses of $3 million.

Q: Who will serve on the New Mango Board following the Closing?

A: The Business Combination Agreement provides that, as of the Closing, the New Mango Board will consist of five directors, three of whom shall be designated by Mango, and of such three at least one of whom shall meet the independent director requirements under Nasdaq rules, and two of whom shall be chosen by Cayson, both of whom shall meet the independent director requirements under Nasdaq rules. These directors will be: Jialing Zhang, currently Mango Financial’s Chairwoman, Cheung Kam Fai, currently Mango’s Director and Chief Executive Officer, and Yawei Cao, David Chung-Hua Bolocan and Taylor Zhang, each of whom will become an independent director of Mango as of the Closing. Messrs. Cao and Zhang are currently Cayson’s Chairman and Chief Executive Officer and Chief Financial Officer, respectively. See “Management of New Mango Following the Business Combination.”

Q: Who will serve as the officers of New Mango following the Closing?

A: The Business Combination Agreement provides that, the officers of Mango as of immediately prior to the Effective Time shall continue as the officers of New Mango after the Effective Time. Those officers are Jialing Zhang, currently Mango Financial’s Chairwomen, Cheung Kam Fai, currently Mango’s Director and Chief Executive Officer, Zhao Pang, currently Mango Financial’s Chief Financial Officer, Yuguo Chen, currently Mango Financial’s Executive Director and Responsible Officer, Tony Tong, currently Mango Financial’s Head of Digital Currency Department, and Chi-Kwan Ying, currently Mango Financial’s Responsible Officer. See “Management of New Mango Following the Business Combination.”

Q: Are there any material differences between Cayson’s M&A and New Mango’s M&A?

A: Yes. Cayson shareholders are being asked to consider and vote upon a proposal to approve, on a non-binding advisory basis, certain material differences between Cayson’s M&A and New Mango’s M&A. The material governance provisions contained in New Mango’s M&A that differ from Cayson’s M&A include, among others, an increase in authorized share capital, the ability of New Mango shareholders to review New Mango’s books and records in certain situations, removing the classified board structure that Cayson had employed:

See “Proposal No. 5: The Non-Binding Governance Proposals,” for additional information.

Q: Is the completion of the Merger subject to any conditions?

A: Yes. The respective obligations of each party to consummate the Business Combination are subject to the fulfillment (or, to the extent permitted by applicable law, waiver) of certain conditions specified in the Business Combination Agreement.

The Business Combination Agreement provides that the obligations of the parties to consummate the Merger are conditioned on, among other things, (i) certain required consents and approvals from governmental authorities, including approval of the SFC, having been obtained, and there being no agreement between Mango or Cayson and any governmental authority pursuant to which Mango or Cayson has agreed not to consummate the Business Combination, (ii) the registration statement filed by Mango with the SEC, of which the accompanying proxy statement/prospectus forms a part, having become effective, (iii) the approval of the proposals to be presented at the Meeting having been obtained, (iv) the listing of the Mango Ordinary Shares having been approved by Nasdaq, subject only to official notice of issuance thereof, (v) no governmental authority of competent jurisdiction having enacted or issued any law (whether temporary, preliminary or permanent), in each case that is in effect and which has the effect of restraining, enjoining or prohibiting the consummation of the transaction, (vi) the Restructuring having been consummated, (vii) the PIPE Financing having been consummated, (viii) Cayson having at least $5,000,001 of net tangible assets, (ix) Mango and Merger Sub, on one hand, and Cayson, on the other hand, having each performed and complied in all material respects with the obligations, covenants and agreements required by the Business Combination Agreement to be performed or complied with by it at or prior to the Effective Time, and (x) the representations and warranties in the Business Combination Agreement of Mango and Merger Sub, on one hand, and Cayson, on the other hand, being true and correct subject to customary bringdown standards. In addition, the obligations of Mango to consummate the Business Combination are conditioned upon, among other items, the resignation of all officers and directors of Cayson, and there having been no “Material Adverse Effect” on Cayson since the date of the Business Combination Agreement, and the obligations of Cayson to consummate the Business Combination are conditioned upon, among other items, there having been no “Material Adverse Effect” on Mango since the date of the Business Combination Agreement. The Business Combination Agreement is also subject to the satisfaction or waiver of certain other closing conditions as described in the accompanying proxy statement/prospectus.

Certain of the foregoing conditions may be waived by the applicable party or parties in writing. To the extent that the Cayson Board or the board of directors of Mango determines that any modifications by the parties, including any waivers of any conditions to the Closing, materially change the terms of the Business Combination, Cayson and Mango will notify their respective shareholders in a manner reasonably calculated to inform them about the modifications as may be required by law, by publishing a press release, and/or filing a current report on Form 8-K and by circulating a supplement to this proxy statement/prospectus to resolicit the votes of Cayson shareholders, if required.

For more information about conditions to the consummation of the Business Combination, see “Proposal No. 1: The Business Combination Proposal —  Business Combination Agreement — Conditions to Closing.”

Q: Does Mango have to pay anything to Cayson if the Business Combination Agreement is terminated?

A: No.

Q: When do you expect the Business Combination to be completed?

A: The Business Combination is expected to be completed in the first half of 2026.

Q: What do I need to do now?

A: Cayson urges you to read this proxy statement/prospectus, including the annexes and the documents referred to herein, carefully and in their entirety and to consider how the Business Combination will affect you as a shareholder of Cayson. Cayson shareholders should then vote as soon as possible in accordance with the instructions provided in this proxy statement/prospectus and on the enclosed proxy card.

Q: When and where will the Meeting be held?

A: The Meeting will be held on [●], 2026 at [●], Eastern Time, virtually via live webcast at [●] and via teleconference at [●] (U.S. toll free) or [●] (international toll free) (in each case using participant code [●]). Cayson encourages its shareholders to attend via live webcast. To participate in the meeting virtually, a Cayson shareholder of record will need the control number included on their proxy card or instructions that accompanied their proxy materials, if applicable, or to obtain a proxy form from their broker, bank or other nominee. The Meeting webcast will begin promptly at [●], Eastern Time. Cayson shareholders are encouraged to access the Cayson Meeting prior to the start time. If you encounter any difficulties accessing the virtual meeting or during the meeting time, please call the technical support number that will be posted on the virtual meeting login page.

Q: How do I attend the Meeting virtually?

A: The Meeting will be held at [●], Eastern Time, on [●], 2026, virtually via live webcast at [●] and via teleconference at [●] (U.S. toll free) or [●] (international toll free) (in each case using participant code [●]), or such other date, time and place to which the Meeting may be adjourned.

To participate in and vote at the virtual meeting, Cayson shareholders of record will need (i) the control number included on their proxy card or instructions that accompanied their proxy materials, if applicable, or (ii) to obtain a proxy form from their broker, bank or other nominee.

The Meeting webcast will begin promptly at [●], Eastern Time. Cayson shareholders are encouraged to access the Meeting prior to the start time. If you encounter any difficulties accessing the virtual meeting or during the meeting time, please call the technical support number that will be posted on the virtual meeting login page.

Q: Who is entitled to vote at the Meeting?

A: Cayson has fixed [●], 2026 as the record date for the Meeting. If you are a Cayson shareholder at the close of business on the record date, you are entitled to vote on matters that come before the Meeting. However, a shareholder may only vote his or her shares if he or she is present in person or is represented by proxy at the Meeting.

Q: How do I vote?

A: If you are a holder of record of Cayson Ordinary Shares on the record date for the Meeting, you may vote at the Meeting in any of the following ways:

If you hold your shares in “street name,” which means your shares are held of record by a broker, bank or nominee, you should contact your broker, bank or nominee to ensure that votes related to the shares you beneficially own are properly counted. In this regard, you must provide the broker, bank or nominee with instructions on how to vote your shares or, if you wish to attend the Meeting and vote in person, obtain a valid proxy from your broker, bank or nominee. In most cases you may vote by telephone or over the Internet as instructed.

Q: If my shares are held in “street name,” will my broker, bank or nominee automatically vote my shares for me?

A: No. If your shares are held in a stock brokerage account or by a bank or other nominee, you are considered the “beneficial holder” of the shares held for you in what is known as “street name.” If this is the case, this proxy statement/prospectus may have been forwarded to you by your brokerage firm, bank or other nominee, or its agent, along with a voting instruction form, and you will need to follow the instructions included on that form in order to instruct your broker, bank or nominee as to how to vote your shares. As the beneficial holder, you have the right to direct your broker, bank or other nominee as to how to vote your shares. Generally, if you do not provide voting instructions to your broker on a particular proposal on which your broker does not have discretionary authority to vote, your shares will not be voted on that proposal. This is called a “broker non-vote.” Your broker would be entitled to vote your shares on other routine proposals where the broker does have discretionary authority to vote. We expect that all proposals being voted on at the Meeting will be considered non-routine under the rules of the New York Stock Exchange (“NYSE”), which generally controls the ability of brokers to vote or not vote shares held in street name on certain matters, and therefore we do not expect any broker non-votes to be submitted. For the same reason, it is important that you instruct your broker, bank or nominee as to how to vote your shares.

Q: How many votes do I have?

A: Cayson shareholders are entitled to one (1) vote at the Meeting for each Cayson Ordinary Share held of record as of the record date. As of the close of business on [●], 2026, the record date, there were [●] Cayson Ordinary Shares issued and outstanding.

Q: What constitutes a quorum?

A: A quorum of Cayson shareholders is necessary to hold a valid meeting. A quorum will be present at the Meeting if one or more shareholders who together hold not less a majority of the issued and outstanding shares of Cayson entitled to attend and vote at the Meeting are present in person (including by virtual attendance) or by proxy (or, in the case of a corporation or other non-natural person, by duly authorized representative or proxy). Based on the Cayson Ordinary Shares issued and outstanding as of the record date, the presence of 3,915,001 Cayson Ordinary Shares will be required to achieve a quorum.

Q: What vote is required to approve each proposal at the Meeting?

A: The following votes are required for each proposal at the Meeting:

Q: What vote of Cayson public shareholders is required to approve the Business Combination Proposal at the Meeting?

A: The Sponsors and Cayson’s officers and directors have agreed to vote all of their shares in favor of the Business Combination. As a result, in addition to such holders, Cayson would need (i) _____ or __%, of the 6,000,000 Public Shares to be voted in favor of the Business Combination Proposal in order to have it approved (assuming all outstanding Cayson shares are voted and the EBC founder shares are voted in favor of the proposal, or (ii) _____ or __%, of the 6,000,000 Public Shares (assuming that only the minimum number of shares representing a quorum are voted at the Meeting and the EBC founder shares are voted in favor of the proposal.

Q: Are the proposals conditioned on one another?

A: Yes. The Merger may be consummated only if the (i) Business Combination Proposal and (ii) the Merger Proposal (collectively, the “Condition Precedent Proposals”) are approved at the Meeting. The approval of each of the Condition Precedent Proposals is cross-conditioned on the approval of the other. The approval of the Nasdaq Proposal and the Non-Binding Governance Proposals also are conditioned on the Condition Precedent Proposals. None of the proposals are conditioned on the approval of the Nasdaq Proposal or the Non-Binding Governance Proposals. However, the Business Combination will not be consummated unless all the proposals are approved or the corresponding condition in the Business Combination Agreement is waived by the parties to such agreement. If the Adjournment Proposal is presented, the other proposals will not be presented. The Non-Binding Governance Proposals are constituted of non-binding advisory proposals.

Q: Do I have dissenters’ rights in connection with the proposed Business Combination?

A: Holders of record of Cayson Ordinary Shares who comply with the applicable requirements of Section 238 of the Cayman Companies Act may have dissenters’ rights in connection with the Merger under the Cayman Companies Act. Cayson shareholders wishing to exercise such statutory dissenter rights and make a demand for payment of the fair value for their Cayson Ordinary Shares must give written notice indicting their objection to the Merger and their intention to exercise their statutory dissenter rights and follow the procedures set out in Section 238 of the Cayman Companies Act, noting that any shareholder upon giving of a notice of dissent shall cease to have any of the rights of a shareholder of the Company except the right to be paid the fair value of his shares and certain other rights pursuant to section 238(7) of the Cayman Companies Act, until such dissenter rights may subsequently be lost and/or extinguished pursuant to the Cayman Companies Act. Since Cayson is a special purpose acquisition company with no assets save for the trust proceeds, in practice, this will be largely similar to the redemption price. Accordingly, Cayson believes that such fair value would equal $[__] (the redemption price per share as of [__], 2026). A Cayson shareholder who elects to exercise dissenters’ rights must do so in respect of all of the Cayson Ordinary Shares that person holds and will lose their right to exercise their redemption rights as described herein. See the section of this proxy statement/prospectus titled “Extraordinary General Meeting of Cayson Shareholders.”

Cayson shareholders are recommended to seek their own legal advice as soon as possible on the application and procedure to be followed in respect of the dissenters’ rights under the Cayman Companies Act.

Q: What are the recommendations of the Cayson Board?

A: The Cayson Board believes that the Business Combination Proposal and the other proposals to be presented at the Meeting are in the best interest of Cayson shareholders and unanimously recommends that its shareholders vote “FOR” the Business Combination Proposal, “FOR” the Merger Proposal, “FOR” the Nasdaq Proposal, “FOR” the Non-Binding Governance Proposals and “FOR” the Adjournment Proposal.

The existence of financial and personal interests of one or more of Cayson’s directors may result in a conflict of interest on the part of such directors between what he, she or they may believe is in the best interests of Cayson and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the proposals. In addition, Cayson’s officers have interests in the Business Combination that may conflict with your interests as a shareholder. For a further discussion of these considerations, see the section entitled “Proposal No. 1: The Business Combination Proposal — Interests of Cayson’s Directors and Executive Officers in the Business Combination.”

Q: Did the Cayson Board obtain a third-party valuation or fairness opinion in determining whether or not to proceed with the Business Combination?

A: Yes. On July 11, 2025, in anticipation of the Cayson Board evaluating the Business Combination, King Kee Appraisal and Advisory Limited (“King Kee”) delivered to the Cayson Board a final draft opinion, which was confirmed by delivery of an final executed opinion, dated July 11, 2025 (the “King Kee Opinion”), to the effect that, as of the date of the King Kee Opinion and based on and subject to various assumptions and limitations described in the opinion, the merger consideration to be paid to the Cayson Shareholders was fair, from a financial point of view, to the Cayson shareholders.

For more information about the King Kee Opinion and the Cayson Board’s decision-making process, see the sections entitled “Proposal No. 1: The Business Combination Proposal – Opinion of King Kee, Fairness Opinion Provider,” “Proposal No. 1: The Business Combination Proposal – Recommendation of the Cayson Board and Reasons for the Business Combination,” and “Proposal No. 1: The Business Combination Proposal – Conflicts of Interest of the Sponsors and Cayson’s Officers and Directors.”

Q: How do the Sponsors intend to vote its shares?

A: The Sponsors and Cayson’s officers and directors have agreed, subject to applicable securities laws, to vote all the Founder Shares and Private Shares (as well as any Public Shares subsequently purchased by them) in favor of the Business Combination and the other proposals to be presented at the Meeting. As of the date of this proxy statement/prospectus, the Sponsors and Cayson’s officers and directors own 1,830,000 of the issued and outstanding Cayson Ordinary Shares.

At any time at or prior to the Business Combination, during a period when they are not then aware of any material nonpublic information regarding Cayson or its securities, the Sponsors or Cayson’s officers, directors or advisors or their respective affiliates may purchase Public Shares from institutional and other investors who vote, or indicate an intention to vote, against any of the proposals presented at the Meeting or who exercise, or indicate an intention to exercise, their redemption rights, or execute agreements to purchase such shares from such investors in the future, or they may enter into transactions with such investors and others to provide them with incentives to acquire Public Shares or vote their Public Shares in favor of the proposals presented at the Meeting or refrain from exercising their redemption rights with respect to their Public Shares. If the Sponsors or Cayson’s directors, officers, advisors or their respective affiliates engage in such transactions prior to the completion of the Business Combination, the purchase will be at a price no higher than the price offered through the redemption process. None of the funds in the trust account will be used to purchase Public Shares in such transactions.

Any such purchase may include a contractual acknowledgement that such shareholder, although still the record holder of the Public Shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights. In the event that the Sponsors or Cayson’s officers, directors or advisors or their respective affiliates purchase Public Shares in privately negotiated transactions from Public Shareholders who have already elected to exercise their redemption rights, such selling shareholder would be required to revoke their prior elections to redeem their Public Shares. If any shares are so purchased, the purchaser will not vote any such shares in favor of approval of the Business Combination Proposal. Additionally, the purchaser will waive any redemption rights with respect to any securities so purchased.

The purpose of such share purchases and other transactions would be (i) to reduce the number of shareholders voting against the Business Combination Proposal and thereby improve the likelihood of approval of the Business Combination Proposal, (ii) to decrease the number of shares that have been or may be submitted for redemption, (iii) to ensure that Cayson’s net tangible assets are at least $5,000,001 either immediately prior to or upon consummation of its initial business combination and after payment of underwriters’ fees and commissions, and (iv) to assist in satisfying certain requirements for listing on Nasdaq that depend on the amount in the trust account and the number of Public Shares outstanding. However, if such purchases are made, the number of beneficial holders of New Mango’s securities may be reduced, and if they are made by affiliates of Cayson, the public “float” of New Mango’s securities may be reduced, either of which may make it more difficult to satisfy other requirements for listing on Nasdaq. If such transactions are effected, the consequence could be to cause the Business Combination to be consummated in circumstances where such consummation could not otherwise occur. Entering into any such arrangements also may have a depressive effect on the market price of Cayson Ordinary Shares. For example, as a result of these arrangements, an investor or holder may have the ability to effectively purchase shares at a price lower than market and may therefore be more likely to sell the shares he or she owns, either at or prior to the Business Combination, at a lower price.

As of the date of this proxy statement/prospectus, there have been no discussions with any investor or holder to effect any such purchases or transaction, and no agreements to such effect have been entered into with any investor or holder.

See the section entitled “Proposal No. 1: The Business Combination Proposal — Potential Purchases of Cayson Securities” for a further discussion of these considerations.

Q: What interests do the Sponsors and Cayson’s officers and directors have in the Business Combination?

A: The personal and financial interests of the Sponsors and Cayson’s officers and directors may have influenced or may in the future influence their motivation in identifying and selecting Mango as a business combination target, completing the Business Combination with Mango and overseeing the operation of the business following the Business Combination. This risk may become more acute as the deadline for completing a business combination nears.

You should keep in mind that the Sponsors and Cayson’s officers and directors have interests in the Business Combination that are different from, or in addition to, those of Public Shareholders generally. These interests include that the Sponsors and Cayson’s officers and directors will lose their entire investment in Cayson if an initial business combination is not completed (other than with respect to Public Shares they may acquire in the future), and that the Sponsors and Cayson’s officers and directors will benefit from the completion of a business combination and may be incentivized to complete a business combination, even if it is with a less favorable target company or on less favorable terms to shareholders, rather than liquidate Cayson. Further, the personal and financial interests of the Sponsors and Cayson’s officers and directors may have influenced their motivation in identifying and selecting Mango as a business combination target and completing the Business Combination with Mango. In considering the Business Combination, Public Shareholders should consider these interests as well as, among other things, the interests described below:

The Cayson Board was aware of and considered these interests, among other matters, in reaching the determination that the Business Combination Agreement and the transactions contemplated thereby, including the Merger, were advisable and in the best interests of, Cayson and its shareholders.

See the section entitled “Proposal 1—The Business Combination Proposal—Interests of Certain Persons in the Business Combination” of this proxy statement/prospectus for a detailed discussion of the special interests that the Sponsors and Cayson directors and officers may have in the Business Combination.

Q: What interests do the Mango officers and directors have in the Business Combination?

A: The personal and financial interests of the Mango officers and directors may have influenced or may in the future influence their motivation in entering into the Business Combination. These include:

Q: What happens if I sell my Cayson Ordinary Shares before the Meeting?

A: The record date for the Meeting is earlier than the date of the Meeting and earlier than the date that the Business Combination is expected to be completed. If you transfer your Public Shares after the applicable record date, but before the Meeting, unless you grant a proxy to the transferee, you will retain your right to vote at such Meeting, but the transferee, and not you, will have the ability to redeem such shares (if time permits).

Q: May I change my vote after I have delivered my signed proxy card or voting instruction card?

A: Yes. If you are a shareholder of record of Cayson Ordinary Shares as of the close of business on the record date, you can change or revoke your proxy before it is voted at the meeting in one of the following ways:

If you are a beneficial holder of Cayson Ordinary Shares held in “street name” as of the close of business on the record date, you can change or revoke your voting instructions by following the instructions provided by your broker or bank.

Q: What happens if I fail to take any action with respect to the Meeting?

A: If you fail to take any action with respect to the Meeting and the Business Combination is approved by shareholders and the Business Combination is consummated, you will become a shareholder of Mango. However, if you fail to vote with respect to the Meeting, you will nonetheless be eligible to elect to redeem your Public Shares in connection with the Business Combination. See “How do I exercise my redemption rights?” above. If you fail to take any action with respect to the Meeting and the Business Combination is not approved, you will remain a holder of Cayson Ordinary Shares and/or Cayson Rights.

Q: What happens if I abstain from voting or do not vote with respect to a proposal?

A: For purposes of the Cayson Meeting, an abstention occurs with respect to a proposal when a shareholder returns a ballot or a proxy and marks “ABSTAIN” with respect to such proposal. If you abstain from voting with respect a proposal, or if you do not vote on a proposal (whether as a result of a broker non-vote or because do not submit a proxy by mail, internet or telephone and do not attend the meeting in person or virtually and vote at the meeting), your abstention or failure to vote will have no effect on the vote on such proposal.

Q: What should I do with the certificates for my Cayson Ordinary Shares, Cayson Rights and/or Cayson Units?

A: Cayson shareholders who exercise their redemption rights must deliver their Public Shares to Continental, either physically (by delivering the certificates for such shares) or electronically, prior to the Meeting. Cayson shareholders who hold their Public Shares as part of Cayson Units and wish to exercise their redemption rights must elect to separate their Cayson Units into the underlying Cayson Ordinary Shares and Cayson Rights in order to deliver their Public Shares and exercise such redemption rights. Holders must complete the procedures for electing to redeem their Public Shares in the manner described above under the question “How do I exercise my redemption rights?” prior to 5:00 p.m., Eastern Time, on [●], 2026 (two (2) business days before the Meeting) in order for their Public Shares to be redeemed.

Holders of Cayson Rights should not submit the certificates relating to their Cayson Rights. In addition, Public Shareholders who do not elect to have their Public Shares redeemed for the pro rata share of the trust account should not submit the certificates relating to their Cayson Ordinary Shares or Cayson Units.

Q: What should I do if I receive more than one set of voting materials?

A: Cayson shareholders may receive more than one set of voting materials, including multiple copies of this proxy statement/prospectus and multiple proxy cards or voting instruction forms. For example, if you hold your shares in more than one brokerage account, you will receive a separate voting instruction form for each brokerage account in which you hold shares. If you are a holder of record and your shares are registered in more than one name, you will receive more than one proxy card. Please complete, sign, date and return each proxy card and voting instruction form that you receive in order to cast a vote with respect to all of your Cayson Ordinary Shares.

Q: Who will solicit and pay the cost of soliciting proxies for the Meeting?

A: The costs and expenses of soliciting proxies from shareholders will be borne by Cayson. Cayson has engaged [●] to assist in the solicitation of proxies for the Meeting. Cayson has agreed to pay a fee of $[●], plus fees and expenses (to be paid with non-trust account funds). Cayson’s employees, officers and directors also may solicit proxies in person, by telephone or by electronic communication. None of these individuals will receive any additional or special compensation for doing this, but they may be reimbursed for reasonable out-of-pocket expenses. In addition, Cayson may reimburse brokerage houses and other custodians, nominees and fiduciaries for their reasonable out-of-pocket expenses for forwarding proxy and solicitation material to the beneficial owners of the Cayson Ordinary Shares.

Q: Where can I find the voting results of the Meeting?

A: Cayson expects to announce the preliminary voting results at the Meeting. Cayson will publish final voting results of the Meeting in a Current Report on Form 8-K within four business days after the Meeting.

Q: Who can help answer my questions?

A: If you have questions about the Business Combination or if you need additional copies of this proxy statement/prospectus, any document incorporated by reference in this proxy statement/prospectus or the enclosed proxy card, you should contact:

[●]

Call Toll Free: [●]
Banks and Brokers Call Collect: [●]
Email: [●]

You also may obtain additional information about Cayson from documents filed with the SEC by following the instructions in the section entitled “Where You Can Find More Information.” If you are a holder of Public Shares and you intend to seek redemption of your Public Shares, you will need to deliver your Public Shares (either physically or electronically) to Continental at the address below prior to the Meeting. Holders must complete the procedures for electing to redeem their Public Shares in the manner described above under the question “How do I exercise my redemption rights?” prior to 5:00 p.m., Eastern Time, on [●], 2026 (two (2) business days before the Meeting) in order for their shares to be redeemed. If you have questions regarding the separation of your Cayson Units or delivery of your Cayson Ordinary Shares, please contact:

Continental Stock Transfer & Trust Company

One State Street Plaza, 30th Floor

New York, New York 10004

E-mail: spacredemptions@continentalstock.com

SUMMARY OF THE PROXY STATEMENT/PROSPECTUS

This summary highlights selected information from this proxy statement/prospectus and may not contain all of the information that is important to you. To better understand the Proposals to be submitted for a vote at the Meeting, whether or not you plan to attend the Meeting, you should read this entire document carefully, including the Business Combination Agreement, attached as Annex A to this proxy statement/prospectus. The Business Combination Agreement is the legal document that governs the Business Combination and the other transactions that will be undertaken in connection therewith. The Business Combination Agreement is also described in detail in this proxy statement/prospectus in the section entitled “Proposal No. 1: The Business Combination Proposal — The Business Combination Agreement.” This proxy statement/prospectus also includes forward-looking statements that involve risks and uncertainties. See “Cautionary Statement Regarding Forward-Looking Statements.”

Parties to the Business Combination

Cayson

Cayson is a Cayman Islands exempted company incorporated on May 27, 2024. Cayson was incorporated for the purpose of effecting a merger, stock exchange, asset acquisition, share purchase, reorganization, or similar business combination with one or more businesses. Cayson’s executive office is located at 205 W 37^th Street, New York, New York 10018 and its telephone number is (203) 998-5540.

On May 29, 2024, Cayson issued an aggregate of 1,725,000 Founder Shares to Cayson Holding for an aggregate purchase price of $25,000. Thereafter, Cayson Holding transferred an aggregate of 862,500 founder shares to Yawei Cao, Cayson’s Chairman and Chief Executive Officer. Cayson also issued 100,000 EBC Founder Shares to EBC for an aggregate purchase price of $1,450 on May 30, 2024.

On September 23, 2024, Cayson consummated the Initial Public Offering of 6,000,000 Cayson Units. Each Cayson Unit consists of one Cayson Ordinary Share and one Cayson Right, each Cayson Right entitling the holder thereof to receive 1/10 of a Cayson Ordinary Share upon the completion of an initial business combination. The Cayson Units were sold at an offering price of $10.00 per unit, generating gross proceeds of $60,000,000.

Simultaneously with the consummation of the Initial Public Offering, Cayson consummated a private placement of 230,000 Private Units at a price of $10.00 per unit, generating total proceeds of $2,300,000. The Private Units were purchased by the Sponsors and their designees. The Private Units are identical to the Cayson Units sold in the Initial Public Offering.

On September 23, 2024, an aggregate of $60,000,000 was deposited in the trust account established with Continental acting as trustee in connection with the Initial Public Offering ($10.00 per unit sold in the offering, including the over-allotment option).

The Cayson Units, Cayson Ordinary Shares and Cayson Rights are currently listed on Nasdaq under the symbols “CAPNU,” “CAPN,” and “CAPNR,” respectively.

Mango

Mango is a Cayman Islands exempted company incorporated on March 28, 2025. Upon completion of the Restructuring, Mango will be a holding company operating the business of Mango Financial. Founded in 1970 during Hong Kong’s industrial boom, Mango Financial was among the first non-foreign securities firms and a founding member of the Far East Exchange—the predecessor of the Hong Kong Stock Exchange. Over the past five decades, Mango Financial has evolved from a traditional trading house into a full-service financial institution, offering investment banking, financial advisory, asset management, and securities underwriting and trading. Mango’s executive office is located at Units 2305-2306, 23/F, Grand Millennium Plaza, 181 Queen’s Road, Central, Sheung Wan, Hong Kong, and its telephone number is (852) 2532 3984.

Following the listing of the Mango Ordinary Shares, Mango will have one class of shares, Mango Ordinary Shares. Holders of Ordinary Shares are entitled to one vote per share.

North Water

North Water is a British Virgin Islands business company incorporated on January 17, 2024. Upon completion of the Restructuring, North Water will become a wholly owned subsidiary of Mango. North Water presently is a holding company operating the business of Mango Financial. North Water’s executive office is located at Units 2305-2306, 23/F, Grand Millennium Plaza, 181 Queen’s Road, Central, Sheung Wan, Hong Kong, and its telephone number is (852) 2532 3984.

Merger Sub

Mango is a Cayman Islands exempted company incorporated on July 3, 2025. Merger Sub was formed solely for the purpose of effectuating the Merger. Merger Sub does not own any material assets and does not operate any business. After the consummation of the Business Combination, Merger Sub will cease to exist as a separate legal entity. Merger Sub’s executive office is located at Units 2305-2306, 23/F, Grand Millennium Plaza, 181 Queen’s Road, Central, Sheung Wan, Hong Kong, and its telephone number is (852) 2532 3984.

The Business Combination Agreement

Business Combination Consideration

At the Effective Time, each outstanding Cayson Ordinary Share, other than shares owned by Cayson and dissenting shares, including the Cayson Ordinary Shares that are components of the Cayson Units and that are issuable in respect of the Cayson Rights, will be automatically converted into one Mango Ordinary Share.

Immediately after the Closing, the Mango shareholders will hold 14,000,000 Mango Ordinary Shares (including the Indemnification Shares), representing an equity value for Mango prior to the Merger of $140,000,000. In addition, the Mango shareholders have the right to receive additional contingent consideration of up to 20,000,000 Earnout Shares upon the achievement of certain net income targets for fiscal years 2025 and 2026.

Of the Mango Ordinary Shares held by the Mango shareholders immediately prior to the Closing, 4,000,000 Indemnification Shares will be deposited into escrow, to be held for two years after the Closing Date as security for certain indemnification obligations of the Mango shareholders.

The following diagram illustrates our corporate structure prior to and after the business combination.

Representations and Warranties; Indemnification

The Merger Agreement contains customary representations and warranties of Cayson and Mango and North Water. All representations and warranties of Mango and North Water will survive for two years after the Closing Date, subject to certain exceptions. The Mango shareholders will indemnify the combined company for any indemnification claims brought in relation to Mango’s representations and warranties contained in the Business Combination Agreement. The indemnification will be capped at an amount equal to 4,000,000 Mango Ordinary Shares and will be subject to a tipping basket of $50,000, subject to certain exceptions.

Covenants of the Parties

The Business Combination Agreement contains certain covenants and agreements of the parties, including, among others, those providing for:

PIPE Investment

Mango and Cayson have agreed to use their reasonable best efforts to enter into definitive agreements for the sale of at least $5,000,000 of equity securities of Cayson in the PIPE Financing to be consummated immediately prior to the Closing. There are currently no commitments for such PIPE Financing.

Conditions to Closing

The Business Combination Agreement provides that the obligations of the parties to consummate the Merger are conditioned on, among other things:

Termination

The Business Combination Agreement may be terminated under certain customary and limited circumstances at any time prior to the Closing, including:

Related Agreements

The Business Combination Agreement contemplates that, at or prior to the Closing, certain of the Mango shareholders will enter into the Lock-Up Agreement, pursuant to which, subject to certain exceptions, no Mango Ordinary Shares may be transferred, sold or assigned by the holders until the date that is six months after the Closing, subject to early release in certain circumstances. These lock-up provisions match the lock-up provisions that are applicable to the shares in Cayson held by the Sponsors.

The Business Combination Agreement also contemplates that, at or prior to the Closing, the Sponsors, certain Cayson shareholders and certain Mango shareholders and Mango will enter into the Registration Rights Agreement and that Continental and New Mango will enter into the Indemnification Escrow Agreement and the Earnout Escrow Agreement.

Pro Forma Voting Power and Implied Ownership Levels

We anticipate that upon the Closing, the Sponsors and their affiliates will own 1,753,000 Mango Ordinary Shares, which would be valued at approximately $[__] million, based on the closing price of the Cayson Ordinary Shares of $[__] per share on [__], 2026.

The tables below show the anticipated ownership of New Mango upon completion of the Business Combination, along with other potential sources of dilution. The tables show the potential impact of redemptions on the share ownership by non-redeeming shareholders in (i) a no redemption scenario, (ii) 25% redemption scenario, (iii) 75% redemption scenario, and (iv) maximum redemption scenario. The levels of ownership presented in the tables below assume that 20,000,000 Earnout Shares have been issued but do not give effect to any PIPE Financing. The information in the tables below has been rounded to the nearest whole number or the nearest decimal. Therefore, the sum of the numbers in a column may not conform exactly to the total figure given for that column in the below table. In addition, certain percentages presented in the tables below reflect calculations based upon the underlying information prior to rounding and, accordingly, may not conform exactly to the percentages that would be derived if the relevant calculations were based upon the rounded numbers or may not sum due to rounding.