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 | — | — | 
                                                1,442,096,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,322,112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                925,354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                140,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                28,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -94,306,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                121,025,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                22,569,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -95,451,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | — | 
                                                121,369,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                28,777,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -90,652,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                3,245,229,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,124,151,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,004,830,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | 
                                                3,691,464,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,842,109,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,485,580,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | 
                                                30.08
                                                
                                             | 
                                                38.48
                                                
                                             | — | 
                                                7.17
                                                
                                             | — | 
                                                -3.54
                                                
                                             | 
                                                -30.33
                                                
                                             | 
| Diluted earnings per share | — | — |  | — |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.879
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.813
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.862
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                320,055,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -37,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -199,615,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -218,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                465,910,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                194,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -291,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -108,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                2,544,459,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,435,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,008,361,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |