Inventories - Schedule of Movement of Inventory Provision /(Reversal) (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
Mar. 31, 2025 CNY (¥)	Mar. 31, 2025 USD ($)	Mar. 31, 2024 CNY (¥)	Mar. 31, 2023 CNY (¥)
Schedule of Movement of Inventory Provision /(Reversal) [Abstract]
At beginning of year	¥ 389		¥ 612	¥ 577
Provision/(reversal)	154	$ 21	(223)	35
At end of year	¥ 543		¥ 389	¥ 612

Amount of inventory reserves for last-in first-out (LIFO) and other inventory valuation methods.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483080/330-10-50-1

Name:	us-gaap_InventoryAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant