Equity-accounted investees (Details) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Disclosure of reserves within equity [line items]
Equity-accounted investees	¥ 491	¥ 0
Share of profit (loss) of associates accounted for using equity method	¥ 18
MynaWallet, Inc.
Disclosure of reserves within equity [line items]
Percentage of voting equity interests acquired	28.70%
au Coincheck Digital Assets, Inc.
Disclosure of reserves within equity [line items]
Percentage of voting equity interests acquired	40.00%

The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]]