Consolidated Statement Of Cash Flows
| Concept | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|
| Consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | — | 
                                                -811,284,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,225,319,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -2,425,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,561,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -1,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -109,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -815,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,227,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -279,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -279,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -33,354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Proceeds from issuance of shares | — | 
                                                1,174,772,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                682,552,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                1,121,527,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                671,365,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                -1,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                306,227,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -589,978,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                833,883,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                527,656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,117,635,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |