v3.26.1
Summary of significant accounting policies (Details)
12 Months Ended
Mar. 31, 2026
USD ($)
Mar. 31, 2025
USD ($)
Mar. 31, 2026
CNY (¥)
Summary of significant accounting policies (Details) [Line Items]      
Liquid investment instruments original maturity duration 3 months    
Cash and cash equivalents $ 415,259 $ 359,043  
Depositor 72,485   ¥ 500,000
Impairment of long-lived assets $ 0 0  
Current liabilities payment due duration 1 year    
Deferred offering cost $ 541,274 0  
Related party transactions immediate family hold percent 10.00%    
Employee benefit expenses $ 48,111 45,754  
Statutory surplus reserve fund description Pursuant to the laws applicable to the PRC, PRC entities must make appropriations from after-tax profit to the non-distributable “statutory surplus reserve fund.” Subject to certain cumulative limits, the “statutory surplus reserve fund” requires annual appropriations of 10% of after-tax profit until the aggregated appropriations reach 50% of the registered capital. For foreign invested enterprises and joint ventures in the PRC, annual appropriations should be made to the “reserve fund.” For foreign invested enterprises, the annual appropriation for the “reserve fund” cannot be less than 10% of after-tax profits until the aggregated appropriations reach 50% of the registered capital. If the Company has accumulated loss from prior periods, the Company is able to use the current period net income after tax to offset against the accumulate loss.    
Value added tax rates range percent 13.00%    
VAT tax authorities duration 5 years    
PRC tax administration and collection law, the statute of limitations duration 3 years    
PRC tax administration and collection law, statute of limitations extended duration 5 years    
Cash $ 415,259 $ 359,043  
Chromarie International Ltd. [Member]      
Summary of significant accounting policies (Details) [Line Items]      
Subsidiary ownership percentage 50.00%   50.00%
Henan Lingbao New Materials Technology Co., Ltd. [Member]      
Summary of significant accounting policies (Details) [Line Items]      
Non-controlling equity interest percent 1.00% 1.00% 1.00%