Key Financial Data Of Reporting Company
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | — | 
                                                7,738,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,489,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                203,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -178,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                4,972,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,476,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,994,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                8,594,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                11,661,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,809,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -103.39
                                                
                                             | 
                                                81.45
                                                
                                             | — | — | 
                                                -52.21
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.5786
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.4696
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.6395
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                361,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                130,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                655,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -69,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -43,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -640,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -901,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                710,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,059,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                721,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |