Quarterly Statement Of Cash Flows
| Concept | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Quarterly statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | 
                                                -524,665,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -464,436,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                42,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -1,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -520,584,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -466,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Net cash provided by (used in) investing activities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,454,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Proceeds from issuance of bonds | 
                                                500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Redemption of bonds | 
                                                -287,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                1,002,619,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                482,034,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -467,781,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                1,539,394,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,057,360,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,063,188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,530,969,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |