Key Financial Data Of Reporting Company
| Concept | 2024-03-01 to 2025-02-28 | 2024-03-01 to 2025-02-28 | As at 2025-02-28 | As at 2025-02-28 | As at 2025-02-28 | As at 2025-02-28 | As at 2025-02-28 | As at 2025-02-28 | As at 2025-02-28 | As at 2025-02-28 | 2023-03-01 to 2024-02-29 | As at 2024-02-29 | 2023-03-01 to 2024-02-29 | As at 2024-02-29 | As at 2023-02-28 | 2022-03-01 to 2023-02-28 | As at 2023-02-28 | 2022-03-01 to 2023-02-28 | As at 2022-02-28 | 2021-03-01 to 2022-02-28 | 2021-03-01 to 2022-02-28 | As at 2022-02-28 | 2020-03-01 to 2021-02-28 | As at 2021-02-28 | As at 2021-02-28 | 2020-03-01 to 2021-02-28 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||||||||||||||||||||
| Business results of reporting company | ||||||||||||||||||||||||||
| Net sales | 
                                                3,229,161,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,462,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                4,845,087,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,462,031,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,588,784,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,364,413,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,239,212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,891,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,025,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,855,439,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | 
                                                -339,156,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -391,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -328,754,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -236,328,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -207,969,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -185,531,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -561,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -476,483,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -440,708,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -254,869,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) | 
                                                -511,710,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -328,073,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -459,988,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -552,238,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -547,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Equity in earnings (losses) of affiliates if equity method is applied | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | — | — | — | 
                                                673,272,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                673,272,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                415,791,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                315,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                280,309,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total number of issued shares | — | — | — | 
                                                3,729,429
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                3,729,429
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                2,636,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | 
                                                2,172,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
                                                2,032,600
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
| Net assets | — | — | — | 
                                                -481,557,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -438,215,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                52,288,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                30,153,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -45,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -156,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                410,672,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                103,302,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,009,689,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                623,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | — | — | — | 
                                                705,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                820,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,505,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,461,164,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,882,658,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,702,806,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,086,277,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,712,633,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,687,706,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,203,828,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets per share | — | — | — | 
                                                -130.40
                                                
                                             | — | — | — | 
                                                -118.66
                                                
                                             | — | — | — | 
                                                -2.55
                                                
                                             | — | 
                                                8.16
                                                
                                             | 
                                                -58.87
                                                
                                             | — | 
                                                -60.26
                                                
                                             | — | 
                                                -15.76
                                                
                                             | — | — | 
                                                48.36
                                                
                                             | — | 
                                                264.81
                                                
                                             | 
                                                312.14
                                                
                                             | — | 
| Dividend paid per share |  | — | — | — | — | — | — | — | — | — | — | — |  | — | — | — | — |  | — | — |  | — | — | — | — |  | 
| Interim dividend paid per share |  | — | — | — | — | — | — | — | — | — | — | — |  | — | — | — | — |  | — | — |  | — | — | — | — |  | 
| Basic earnings (loss) per share | 
                                                -138.56
                                                
                                             | 
                                                -93.90
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -123.69
                                                
                                             | — | 
                                                -109.30
                                                
                                             | — | — | 
                                                -149.42
                                                
                                             | — | 
                                                -215.19
                                                
                                             | — | 
                                                -297.86
                                                
                                             | 
                                                -276.58
                                                
                                             | — | 
                                                -320.81
                                                
                                             | — | — | 
                                                -272.16
                                                
                                             | 
| Diluted earnings per share |  |  | — | — | — | — | — | — | — | — |  | — |  | — | — |  | — |  | — |  |  | — |  | — | — |  | 
| Equity-to-asset ratio | — | — | — | 
                                                -0.6827
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.5340
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.0063
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0206
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.0813
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.0920
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.0161
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0603
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.1967
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.2827
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Rate of return on equity | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -1.5204
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.7650
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                -0.6157
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Price-earnings ratio | 
                                                -2.15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -3.17
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -4.41
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -4.99
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                -2.92
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -2.03
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -1.51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -1.63
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -2.35
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                -2.77
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Payout ratio | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | — | 
                                                -402,253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -28,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,530,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -434,737,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                154,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                523,508,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -137,070,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -318,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -42,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -685,856,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -105,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                95,214,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -7,917,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                132,080,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                588,384,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | — | — | 
                                                64,427,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                48,841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                119,341,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                441,193,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                786,669,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | — | — | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                34
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                34
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                64
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                17
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                67
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                52
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                175
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                159
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                112
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                105
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                383
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Average number of temporary employees | — | — | — | 
                                                21
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                21
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                21
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                37
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                16
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                28
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Total shareholder return | — | — | — | 
                                                0.378
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0.293
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.235
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.242
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.407
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Total return on share price index | — | — | — | 
                                                2.022
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1.880
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1.366
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                1.259
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1.218
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |