Key Financial Data Of Reporting Company
| Concept | 2020-10-01 to 2021-06-30 | As at 2021-06-30 | 2021-04-01 to 2021-06-30 | 2019-10-01 to 2020-09-30 | As at 2020-09-30 | As at 2020-06-30 | 2020-04-01 to 2020-06-30 | 2019-10-01 to 2020-06-30 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | 
                                                1,712,459,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,979,825,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,108,541,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | 
                                                -107,413,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -583,378,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -417,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) | 
                                                -134,132,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -777,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -443,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Equity in earnings (losses) of affiliates if equity method is applied | 
                                                -22,626,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -19,069,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -12,181,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | — | 
                                                2,624,632,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,992,531,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,992,531,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total number of issued shares | — | 
                                                10,303,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                8,303,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                8,303,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
| Net assets | — | 
                                                2,838,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,709,388,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,042,725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                3,158,296,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,073,338,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,872,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividend paid per share |  | — | — |  | — | — | — |  | 
| Basic earnings (loss) per share | 
                                                -15.42
                                                
                                             | — | 
                                                3.73
                                                
                                             | 
                                                -105.42
                                                
                                             | — | — | 
                                                -22.54
                                                
                                             | 
                                                -62.37
                                                
                                             | 
| Diluted earnings per share |  | — | — |  | — | — | — |  | 
| Equity-to-asset ratio | — | 
                                                0.899
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.824
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.711
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |