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 | — | 
                                                16,942,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,726,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,892,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                686,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,066,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                572,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                23,075,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,831,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                44,122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                43,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                42,475,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                86.79
                                                
                                             | 
                                                153.32
                                                
                                             | — | — | 
                                                76.41
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.523
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.529
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -601,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,369,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                210,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -244,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -462,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -367,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                692,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -283,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                363,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                2,878,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,025,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,605,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |