Employee Benefits (Details) - CNY (¥) ¥ in Millions	12 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Employee Benefits [Abstract]
Employee benefits costs	¥ 6	¥ 8	¥ 9

Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit. Other employee benefit expense includes, but is not limited to, service component of net periodic benefit cost for defined benefit plan. Excludes compensation cost in cost of good and service sold.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 48
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482785/280-10-55-48

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Name:	us-gaap_CompensationExpenseExcludingCostOfGoodAndServiceSold
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration