v3.26.3
Share-Based Compensation - Schedule of Award Activity (Details)
12 Months Ended
Apr. 30, 2026
USD ($)
$ / shares
shares
Apr. 30, 2026
JPY (¥)
¥ / shares
shares
Apr. 30, 2025
USD ($)
$ / shares
shares
Apr. 30, 2025
JPY (¥)
¥ / shares
shares
Apr. 30, 2024
JPY (¥)
¥ / shares
shares
Apr. 30, 2026
JPY (¥)
¥ / shares
shares
2019 Plan Member]            
Share-Based Compensation [Line Items]            
Number of options, Granted    
Weighted- average exercise price, Granted (in Yen per share and Dollars per share) | ¥ / shares        
Aggregate intrinsic Value, Granted (in Yen and Dollars) | ¥        
Number of options, Forfeited (1,020,000) (1,020,000)    
Weighted- average exercise price, Forfeited (in Yen per share and Dollars per share) | ¥ / shares   ¥ 2      
Weighted- average remaining contractual term, Forfeited        
Aggregate intrinsic Value, Forfeited (in Yen and Dollars) | ¥        
Number of options, Outstanding 0 0 1,020,000 1,020,000 1,020,000  
Weighted- average exercise price, Outstanding (in Yen per share and Dollars per share) | ¥ / shares   ¥ 2   ¥ 2 ¥ 2  
Weighted- average remaining contractual term, Outstanding 2 years 9 months 18 days 2 years 9 months 18 days 3 years 9 months 18 days 3 years 9 months 18 days 4 years 9 months 18 days  
Aggregate intrinsic Value, Outstanding (in Yen and Dollars) | ¥   ¥ 251.2   ¥ 52.5 ¥ 121.4  
Number of options, Vested 0 0 1,020,000 1,020,000    
Weighted- average exercise price, Vested (in Yen per share and Dollars per share) | ¥ / shares   ¥ 2   ¥ 2    
Weighted- average remaining contractual term, Vested 2 years 9 months 18 days 2 years 9 months 18 days 3 years 9 months 18 days 3 years 9 months 18 days    
Aggregate intrinsic Value, Vested (in Yen and Dollars) | ¥   ¥ 251.2   ¥ 52.5    
Number of options, Exercisable 0     1,020,000   0
Weighted- average exercise price, Exercisable (in Yen per share and Dollars per share) | ¥ / shares       ¥ 2   ¥ 2
Weighted- average remaining contractual term, Exercisable 2 years 9 months 18 days 2 years 9 months 18 days 3 years 9 months 18 days 3 years 9 months 18 days    
Aggregate intrinsic Value, Exercisable (in Yen and Dollars) | ¥       ¥ 52.5   ¥ 251.2
2019 Plan Member] | United States of America, Dollars            
Share-Based Compensation [Line Items]            
Number of options, Granted        
Weighted- average exercise price, Granted (in Yen per share and Dollars per share) | $ / shares          
Aggregate intrinsic Value, Granted (in Yen and Dollars) | $          
Number of options, Forfeited (1,020,000) (1,020,000)        
Weighted- average exercise price, Forfeited (in Yen per share and Dollars per share) | $ / shares $ 0.01          
Weighted- average remaining contractual term, Forfeited        
Aggregate intrinsic Value, Forfeited (in Yen and Dollars) | $          
Number of options, Outstanding 1,020,000 1,020,000    
Weighted- average exercise price, Outstanding (in Yen per share and Dollars per share) | $ / shares $ 0.01   $ 0.01      
Weighted- average remaining contractual term, Outstanding 2 years 9 months 18 days 2 years 9 months 18 days 3 years 9 months 18 days 3 years 9 months 18 days    
Aggregate intrinsic Value, Outstanding (in Yen and Dollars) | $ $ 1.6   $ 0.3      
Number of options, Vested        
Weighted- average exercise price, Vested (in Yen per share and Dollars per share) | $ / shares $ 0.01          
Weighted- average remaining contractual term, Vested 2 years 9 months 18 days 2 years 9 months 18 days        
Aggregate intrinsic Value, Vested (in Yen and Dollars) | $ $ 1.6          
Number of options, Exercisable        
Weighted- average exercise price, Exercisable (in Yen per share and Dollars per share) | $ / shares $ 0.01          
Weighted- average remaining contractual term, Exercisable 2 years 9 months 18 days 2 years 9 months 18 days        
Aggregate intrinsic Value, Exercisable (in Yen and Dollars) | $ $ 1.6          
2019 Trust-Type Plan [Member]            
Share-Based Compensation [Line Items]            
Number of options, Granted    
Weighted- average exercise price, Granted (in Yen per share and Dollars per share) | ¥ / shares        
Aggregate intrinsic Value, Granted (in Yen and Dollars) | ¥        
Number of options, Forfeited (1,960,000) (1,960,000)    
Weighted- average exercise price, Forfeited (in Yen per share and Dollars per share) | ¥ / shares     ¥ 50    
Weighted- average remaining contractual term, Forfeited    
Aggregate intrinsic Value, Forfeited (in Yen and Dollars) | ¥        
Number of options, Exercised    
Weighted- average exercise price,Exercised (in Yen per share and Dollars per share) | ¥ / shares        
Aggregate intrinsic Value, Exercised (in Yen and Dollars) | ¥        
Number of options, Outstanding     1,960,000  
Weighted- average exercise price, Outstanding (in Yen per share and Dollars per share) | ¥ / shares       ¥ 50  
Weighted- average remaining contractual term, Outstanding     5 years 2 months 12 days  
Aggregate intrinsic Value, Outstanding (in Yen and Dollars) | ¥       ¥ 73.4  
Number of options, Vested        
Weighted- average exercise price, Vested (in Yen per share and Dollars per share) | ¥ / shares          
Weighted- average remaining contractual term, Vested        
Aggregate intrinsic Value, Vested (in Yen and Dollars) | ¥