v3.26.1
Cover
 6 Months Ended
Sep. 30, 2025
Entity Addresses [Line Items]  
Document Type F-4/A
Amendment Flag true
Amendment Description Amendment 2
Entity Registrant Name YHNA MS I LIMITED
Entity Central Index Key 0002067919
Entity Incorporation, State or Country Code E9
Entity Address, Address Line One Room 2701, Building 6
Entity Address, Address Line Two Oumei Financial City
Entity Address, Address Line Three Cangqian Street
Entity Address Address Line four Yuhang District
Entity Address, City or Town Hangzhou City
Entity Address, Country CN
Entity Address, Postal Zip Code 0000
Entity Emerging Growth Company true
Elected Not To Use the Extended Transition Period false
Business Contact [Member]  
Entity Addresses [Line Items]  
Entity Address, Address Line One 122 East 42nd Street
Entity Address, Address Line Two 18th Floor
Entity Address, City or Town New York
Entity Address, State or Province NY
Entity Address, Postal Zip Code 10168
City Area Code 800
Local Phone Number 221-0102
Contact Personnel Name Cogency Global Inc.