Key Financial Data Of Reporting Company
| Concept | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | 2023-10-01 to 2023-12-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-10-01 to 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | 
                                                6,079,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,024,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,889,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                187,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -23,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                45,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                10,433,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,280,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,586,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                14,656,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                14,987,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,068,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                42.46
                                                
                                             | — | 
                                                8.99
                                                
                                             | — | 
                                                -259.79
                                                
                                             | — | 
                                                -85.87
                                                
                                             | 
                                                -103.31
                                                
                                             | 
| Diluted earnings per share |  | — | — | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.712
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.686
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.703
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |