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 | — | 
                                                8,981,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,096,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,627,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -190,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,457,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                25,566,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,151,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                31,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                36,984,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,235,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -30.51
                                                
                                             | 
                                                413.15
                                                
                                             | — | — | 
                                                29.96
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.801
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.707
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.804
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                4,649,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                730,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,730,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -199,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -148,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -329,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -316,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                10,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,071,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,604,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |