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 | — | — | 
                                                8,726,643,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                15,414,519,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,095,169,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                98,734,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -95,901,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -87,803,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                62,439,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -72,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -43,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | — | 
                                                122,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -51,960,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -96,708,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                10,856,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,782,302,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,782,737,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | 
                                                19,212,202,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,359,870,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,546,686,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | 
                                                -4.77
                                                
                                             | 
                                                10.36
                                                
                                             | — | 
                                                -11.86
                                                
                                             | — | 
                                                -3.38
                                                
                                             | 
                                                -7.07
                                                
                                             | 
| Diluted earnings per share | — | — |  | — |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.564
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.586
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.578
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                199,717,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -674,657,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,272,564,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -239,655,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,405,146,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -977,107,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -111,697,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,794,611,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,717,596,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                1,200,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,350,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,103,784,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |