Key Financial Data Of Reporting Company
| Concept | As at 2023-09-30 | 2023-07-01 to 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-09-30 | 2022-07-01 to 2022-09-30 | 2022-04-01 to 2022-09-30 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | — | — | 
                                                4,089,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,024,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,102,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -23,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                10,501,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,280,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,762,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | 
                                                14,867,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                14,987,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,173,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | 
                                                34.76
                                                
                                             | 
                                                33.32
                                                
                                             | — | 
                                                -259.79
                                                
                                             | — | 
                                                -15.66
                                                
                                             | 
                                                17.65
                                                
                                             | 
| Diluted earnings per share | — | — |  | — |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.706
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.686
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.709
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -873,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                241,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                176,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -614,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -137,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                283,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -80,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -33,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -33,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                2,844,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,412,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,769,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |