Key Financial Data Of Reporting Company
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Operating revenue | — | 
                                                2,780,650,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,219,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,429,532,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                448,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                995,087,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                442,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                7,558,667,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,373,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,893,387,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                11,778,005,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                11,818,116,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,159,154,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                190.33
                                                
                                             | 
                                                379.00
                                                
                                             | — | — | 
                                                161.31
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.638
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.620
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.603
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -48,629,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,461,301,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                649,150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -8,981,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -490,376,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -5,678,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -332,696,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -90,331,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -358,963,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                2,124,649,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,528,061,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,898,999,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |