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 | ||||||
| Net sales | — | 
                                                129,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                682,464,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                169,404,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -303,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,217,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -227,433,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                1,247,567,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,157,723,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,562,132,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                1,753,934,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,751,454,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,085,676,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -5.60
                                                
                                             | 
                                                -24.62
                                                
                                             | — | — | 
                                                -4.70
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.704
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.651
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.743
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |