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 | — | 
                                                5,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,332,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,328,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -72,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                282,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -199,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                5,384,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,553,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,955,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                12,258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                13,362,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,858,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -22.03
                                                
                                             | 
                                                63.46
                                                
                                             | — | — | 
                                                -36.19
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.4019
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.3801
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.3810
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                279,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                289,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                75,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -168,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -192,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -67,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -139,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -66,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                43,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                271,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                299,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                320,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |