Key Financial Data Of Reporting Company
| Concept | 2024-01-01 to 2024-03-31 | As at 2024-03-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | 
                                                880,892,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,648,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                786,292,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                32,950,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                298,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,451,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                2,917,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,942,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,977,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                4,095,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,305,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,032,185,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                8.12
                                                
                                             | — | 
                                                32.87
                                                
                                             | — | 
                                                15.35
                                                
                                             | — | 
| Diluted earnings per share |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.712
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.683
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.739
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |