Key Financial Data Of Reporting Company
| Concept | 2023-07-01 to 2024-06-30 | As at 2024-06-30 | As at 2024-06-30 | 2023-07-01 to 2024-06-30 | As at 2023-06-30 | As at 2023-06-30 | 2022-07-01 to 2023-06-30 | 2022-07-01 to 2023-06-30 | 2021-07-01 to 2022-06-30 | 2021-07-01 to 2022-06-30 | As at 2022-06-30 | As at 2022-06-30 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||||||
| Business results of reporting company | ||||||||||||
| Net sales | 
                                                34,131,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                912,540,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                730,360,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,580,164,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,112,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,144,937,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary profit (loss) | 
                                                1,988,988,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                555,972,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                328,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,353,255,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,202,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                790,274,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Profit (loss) | — | — | — | 
                                                547,037,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                366,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                788,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | 
                                                2,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | 
                                                8,420,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                8,420,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                8,420,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | 
                                                9,138,220,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,486,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,078,754,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,856,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                9,946,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,234,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                9,257,624,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,045,057,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,145,045,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,025,185,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                19,585,553,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,277,135,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | 
                                                1,126.51
                                                
                                             | 
                                                1,663.52
                                                
                                             | — | 
                                                1,126.19
                                                
                                             | 
                                                1,471.35
                                                
                                             | — | — | — | — | 
                                                1,240.16
                                                
                                             | 
                                                1,151.17
                                                
                                             | 
| Dividend paid per share | — | — | — | 
                                                65.00
                                                
                                             | — | — | 
                                                70.00
                                                
                                             | — | — | 
                                                70.00
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — |  | — | — |  | — | — |  | — | — | 
| Basic earnings (loss) per share | 
                                                192.81
                                                
                                             | — | — | 
                                                67.72
                                                
                                             | — | — | 
                                                45.71
                                                
                                             | 
                                                218.71
                                                
                                             | 
                                                188.44
                                                
                                             | 
                                                96.36
                                                
                                             | — | — | 
| Diluted earnings per share | 
                                                192.19
                                                
                                             | — | — | 
                                                67.51
                                                
                                             | — | — | 
                                                45.56
                                                
                                             | 
                                                218.01
                                                
                                             | 
                                                187.39
                                                
                                             | 
                                                95.84
                                                
                                             | — | — | 
| Equity-to-asset ratio | — | 
                                                0.985
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.560
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.991
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.563
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.506
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.992
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | 
                                                0.123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.060
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.040
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.161
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.152
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.086
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Price-earnings ratio | 
                                                8.43
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                23.99
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                30.26
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6.32
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5.65
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11.05
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Payout ratio | — | — | — | 
                                                0.9598
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1.5316
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.7265
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -1,916,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                793,985,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                608,102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -127,557,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -347,380,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -978,204,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -111,022,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -788,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -606,209,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | 
                                                2,116,895,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,266,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,604,749,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Number of employees | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,453
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,393
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                1,359
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                392
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                294
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total shareholder return | — | 
                                                1.6573
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1.3643
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | 
                                                1.5785
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1.2569
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |