Guarantee Deposits - Schedule of Guarantee Deposits (Parenthetical) (Details) - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Guarantee Deposits [Abstract] | ||
| Percentage requirement for unused prepaid balance of money | 100.00% | |
| Percentage requirement for unused prepaid balance of lite | 50.00% | |
| Guarantee deposits including government securities and cash held by the trust | ¥ 306,747 | ¥ 250,329 |
| Deposits with bank | 196,500 | |
| Safeguarding assets maintained with digital wage payment services amount | ¥ 5,011 | ¥ 5,002 |