v3.26.1
Summary of principal accounting policies (Details Narrative)
6 Months Ended 12 Months Ended
Sep. 30, 2025
USD ($)
Sep. 30, 2025
CNY (¥)
Sep. 30, 2024
CNY (¥)
Mar. 31, 2025
USD ($)
Mar. 31, 2025
CNY (¥)
Mar. 31, 2024
USD ($)
Mar. 31, 2024
CNY (¥)
Mar. 31, 2023
CNY (¥)
Sep. 30, 2025
CNY (¥)
Mar. 31, 2025
CNY (¥)
Property, Plant and Equipment [Line Items]                    
Convenience translation, description the convenience of the readers and were calculated at the rate of USD1.00=RMB7.119 the convenience of the readers and were calculated at the rate of USD1.00=RMB7.119   the convenience of the readers and were calculated at the rate of USD1.00=RMB7.119 the convenience of the readers and were calculated at the rate of USD1.00=RMB7.119          
Non-controlling interests $ 19,320     $ 30,789     ¥ 0   ¥ 137,537 ¥ 219,174
Impairment of long-lived assets   ¥ 0     ¥ 0   0      
Deferred offering costs 826,826     531,206     1,599,851   5,886,177 3,781,659
Impairment for operating lease right-of-use lease assets   0 ¥ 0   0   0      
Contract liabilities 1,215,199     1,475,309     27,893,632   8,651,000 10,502,722
Revenue recognized included in contract liabilities   (1,851,722) 27,893,632   54,601,458 $ 3,918,195 27,893,632 ¥ 1,082,404    
Employee benefit expenses 127,535 907,923 484,097 144,592 1,029,354   654,722      
Under payment of taxes 14,047     $ 14,047         100,000 ¥ 100,000
Other comprehensive loss   ¥ 0 ¥ 0   ¥ 0   ¥ 0      
[custom:ContractsWithCustomerLiability-0] $ 260,110               ¥ 1,851,722  
Minimum [Member]                    
Property, Plant and Equipment [Line Items]                    
VAT rates 3.00% 3.00%   3.00% 3.00%          
Maximum [Member]                    
Property, Plant and Equipment [Line Items]                    
VAT rates 6.00% 6.00%   6.00% 6.00%