Key Financial Data Of Group
| 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 group | ||||||||
| Business results of group | ||||||||
| Net sales | — | — | 
                                                15,892,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                31,280,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,112,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                572,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,044,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                438,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                451,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                832,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                416,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | — | 
                                                504,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                953,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                411,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                22,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                21,713,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                21,290,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | 
                                                42,475,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                42,006,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                41,690,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | 
                                                55.67
                                                
                                             | 
                                                76.41
                                                
                                             | — | 
                                                140.87
                                                
                                             | — | 
                                                47.05
                                                
                                             | 
                                                70.52
                                                
                                             | 
| Diluted earnings per share | — | — |  | — |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.517
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.511
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                210,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                583,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                89,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -367,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -617,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                363,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -390,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                229,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                2,605,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,392,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,884,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |