v3.26.1
Concentration of risks (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
CNY (¥)
Sep. 30, 2025
CNY (¥)
Mar. 31, 2025
CNY (¥)
Concentration Risk [Line Items]                
Cash $ 195,730     $ 2,328,969   ¥ 15,642,560 ¥ 1,393,400 ¥ 16,579,930
Cash, FDIC Insured Amount             500,000 500,000
Cash, Uninsured Amount 89,860         12,885,487 ¥ 639,715 0
Total revenues $ 7,092,302 ¥ 50,490,097 ¥ 42,299,076 $ 15,449,939 ¥ 109,988,114 41,606,354    
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Major Customers [Member]                
Concentration Risk [Line Items]                
Total revenues   ¥ 0 ¥ 0     ¥ 0    
Percentage of revenue 10.00% 10.00% 10.00%     10.00%    
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Major One Supplier [Member]                
Concentration Risk [Line Items]                
Percentage of revenue 65.10% 65.10% 37.90% 14.70% 14.70%      
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Major Two Supplier [Member]                
Concentration Risk [Line Items]                
Percentage of revenue 12.50% 12.50% 33.80% 10.50% 10.50%      
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Major Three Supplier [Member]                
Concentration Risk [Line Items]                
Percentage of revenue     10.40% 13.70% 13.70%      
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Major Four Supplier [Member]                
Concentration Risk [Line Items]                
Percentage of revenue       10.10% 10.10%      
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Major Five Supplier [Member]                
Concentration Risk [Line Items]                
Percentage of revenue       13.40% 13.40%      
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Major Six Supplier [Member]                
Concentration Risk [Line Items]                
Percentage of revenue       14.50% 14.50%      
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | One Suppliers [Member]                
Concentration Risk [Line Items]                
Percentage of revenue 79.30% 79.30%       34.20%    
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Two Suppliers [Member]                
Concentration Risk [Line Items]                
Percentage of revenue       14.60% 14.60% 32.60%    
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Suppliers [Member]                
Concentration Risk [Line Items]                
Accounts Receivable, after Allowance for Credit Loss           ¥ 0   ¥ 0
Accounts Payable [Member] | Customer Concentration Risk [Member] | Suppliers [Member]                
Concentration Risk [Line Items]                
Percentage of revenue       10.00% 10.00% 10.00%