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 | — | — | 
                                                13,114,139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                25,516,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,715,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                1,941,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,121,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,699,729,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                1,241,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,564,483,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,297,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | — | 
                                                2,146,658,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,777,073,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,568,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                60,267,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                57,368,892,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                57,511,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | 
                                                108,173,558,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                100,403,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                103,186,717,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | — | 
                                                11.16
                                                
                                             | 
                                                24.77
                                                
                                             | — | 
                                                31.28
                                                
                                             | — | 
                                                10.40
                                                
                                             | 
                                                25.95
                                                
                                             | 
| Diluted earnings per share | — | — | 
                                                24.75
                                                
                                             | — | 
                                                31.21
                                                
                                             | — | — | 
                                                25.89
                                                
                                             | 
| Equity-to-asset ratio | 
                                                0.533
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.545
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.532
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -977,049,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,017,293,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,055,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -2,864,202,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,198,401,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,657,075,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                3,326,226,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -4,460,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,110,545,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                8,276,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,598,633,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,096,821,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |