Key Financial Data Of Group
| Concept | As at 2024-03-31 | 2024-01-01 to 2024-03-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2023-03-31 | 2023-01-01 to 2023-03-31 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Ordinary profit (loss) | — | 
                                                -339,567,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,127,594,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -493,787,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                5,349,775,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,687,452,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,806,221,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                5,456,992,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,778,946,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,008,290,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -7.86
                                                
                                             | 
                                                -27.25
                                                
                                             | — | — | 
                                                -12.49
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.979
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.983
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.948
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |