Key Financial Data Of Reporting Company
| Concept | 2024-01-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | 
|---|---|---|---|---|
| Key financial data of reporting company | ||||
| Business results of reporting company | ||||
| Net sales | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | 
                                                -230,771,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                344,184,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) | 
                                                -233,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                260,330,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Equity in earnings (losses) of affiliates if equity method is applied | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | — | 
                                                854,087,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                854,087,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total number of issued shares | — | 
                                                11,604,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                11,604,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                2,871,319,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,104,768,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | — | 
                                                2,972,056,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,313,902,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividend paid per share |  | — | — |  | 
| Basic earnings (loss) per share | 
                                                -20.12
                                                
                                             | — | — | 
                                                25.42
                                                
                                             | 
| Diluted earnings per share |  | — | — | 
                                                23.07
                                                
                                             | 
| Equity-to-asset ratio | — | 
                                                0.966
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.937
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |