Earnings Per Share - Schedule of Basis for Calculation of Basic and Diluted Earnings Per Share (Details) - JPY (¥) ¥ / shares in Units, shares in Thousands, ¥ in Millions |
12 Months Ended | ||||
|---|---|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2024 |
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| Basic earnings per share [abstract] | |||||
| Profit (loss) for the year attributable to owners of the parent company - Basic | ¥ 115,034 | ¥ 36,170 | ¥ (3,350) | ||
| Weighted average number of issued common shares for the year - Basic | 637,577 | 550,000 | 550,000 | ||
| Basic earnings (loss) per share | [1] | ¥ 180.42 | ¥ 65.76 | ¥ (6.09) | |
| Diluted earnings per share [abstract] | |||||
| Profit (loss) for the year attributable to owners of the parent company - Diluted | ¥ 115,034 | ¥ 36,170 | ¥ (3,350) | ||
| Weighted average number of issued common shares for the year | 637,577 | 550,000 | 550,000 | ||
| Effects of dilutive potential common shares | 6,682 | 0 | 0 | ||
| Weighted average number of ordinary shares used in calculating diluted earnings per share | 644,259 | 550,000 | 550,000 | ||
| Diluted earnings (loss) per share | [1] | ¥ 178.55 | ¥ 65.76 | ¥ (6.09) | |
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