Consolidated Statement Of Cash Flows
| Concept | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                -501,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -642,014,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -629,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -628,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                76,690,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Foreign exchange losses (gains) | — | — | 
                                                37,534,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                -818,329,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -448,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                -44,424,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,695,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -5,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,901,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -812,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -451,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                2,601,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                65,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                10,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Purchase of property, plant and equipment | — | — | 
                                                -80,196,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -23,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -119,992,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -34,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Proceeds from issuance of shares | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,842,027,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of treasury shares | — | — | 
                                                -572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -268,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                145,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,125,418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | — | 
                                                -949,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,014,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                -788,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,640,373,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                4,793,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,582,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,941,896,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |