Financial risk management - Summary of Price Sensitivity Analysis (Detail) - Trading equity securities [member] - Equity price risk [member] - JPY (¥) ¥ in Millions	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Disclosure of sensitivity analysis of fair value measurement to changes in unobservable inputs, assets [line items]
Income before income taxes	¥ (47,269)	¥ (24,621)
Other comprehensive income (before considering the tax effects)	¥ (8,114)	¥ (6,116)
Decreased market prices of marketable equity instruments	10.00%	10.00%

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No definition available.

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- Definition

The amount of increase (decrease) in the fair value measurement of assets, recognised in other comprehensive income before tax, due to a reasonably possible decrease in an unobservable input. [Refer: Tax income (expense)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 13
-IssueDate 2024-01-01
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The amount of increase (decrease) in the fair value measurement of assets, recognised in profit or loss before tax, due to a reasonably possible decrease in an unobservable input. [Refer: Tax income (expense)]

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- Definition

The percentage of a reasonably possible decrease in an unobservable input used in fair value measurement of assets.

+ References

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