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 | ||||||
| Ordinary profit (loss) | — | 
                                                2,862,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,725,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,690,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                66,502,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                65,594,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                98,213,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                117,351,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                89,638,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                82.07
                                                
                                             | 
                                                310.37
                                                
                                             | — | — | 
                                                48.46
                                                
                                             | 
| Diluted earnings per share | — | 
                                                81.88
                                                
                                             | 
                                                309.66
                                                
                                             | — | — | 
                                                48.35
                                                
                                             | 
| Equity-to-asset ratio | 
                                                0.676
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.558
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.646
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                10,037,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -13,562,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -8,613,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -783,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -733,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -10,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,521,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -5,144,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                13,667,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                13,481,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,809,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |