Key Financial Data Of Group
| Concept | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | 2023-10-01 to 2023-12-31 | 
|---|---|---|---|
| Key financial data of group | |||
| Business results of group | |||
| Net sales | 
                                                15,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary profit (loss) | 
                                                -500,601,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Profit (loss) attributable to owners of parent | 
                                                -503,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Comprehensive income | 
                                                -503,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net assets | — | 
                                                6,040,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | — | 
                                                6,233,108,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | 
                                                -70.15
                                                
                                             | — | 
                                                -22.39
                                                
                                             | 
| Diluted earnings per share |  | — | — | 
| Equity-to-asset ratio | — | 
                                                0.9676
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |