Earnings per share (Details) - JPY (¥) ¥ / shares in Units, ¥ in Millions	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2024
Earnings per share [abstract]
Profit (loss), attributable to ordinary equity holders of parent entity, used in calculating basic earnings per share	¥ (1,833)	¥ (14,350)	¥ 1,967
Profit (loss), attributable to ordinary equity holders of parent entity, used in calculating diluted earnings per share	¥ (1,833)	¥ (14,350)	¥ 1,967
Basic net earnings (losses) per share (in Yen per share)	¥ (13.52)	¥ (114.98)	¥ 16.05
Diluted net earnings (losses) per share (in Yen per share)	¥ (13.52)	¥ (114.98)	¥ 16.05
Weighted-average number of shares, basic (in shares)	135,583,521	124,803,262	122,587,617
Weighted-average number of shares, diluted (in shares)	135,583,521	124,803,262	122,587,617

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator) divided by the weighted average number of ordinary shares outstanding during the period (the denominator).

+ References

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The amount of profit (loss) attributable to ordinary equity holders of the parent entity (the numerator), divided by the weighted average number of ordinary shares outstanding during the period (the denominator), both adjusted for the effects of all dilutive potential ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

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The profit (loss) attributable to ordinary equity holders of the parent entity. [Refer: Profit (loss)]

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The profit (loss) attributable to ordinary equity holders of the parent entity, adjusted for the effects of all dilutive potential ordinary shares. [Refer: Profit (loss)]

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The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

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