Key Financial Data Of Group
| Concept | As at 2024-01-31 | 2023-02-01 to 2024-01-31 | 2023-02-01 to 2024-01-31 | As at 2024-01-31 | As at 2023-01-31 | As at 2023-01-31 | 2022-02-01 to 2023-01-31 | 2022-02-01 to 2023-01-31 | 2021-02-01 to 2022-01-31 | 2021-02-01 to 2022-01-31 | As at 2022-01-31 | As at 2022-01-31 | As at 2021-01-31 | 2020-02-01 to 2021-01-31 | As at 2021-01-31 | 2020-02-01 to 2021-01-31 | 2019-02-01 to 2020-01-31 | 2019-02-01 to 2020-01-31 | As at 2020-01-31 | As at 2020-01-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | ||||||||||||||||||||
| Business results of group | ||||||||||||||||||||
| Net sales | — | 
                                                4,087,093,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,415,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,299,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,655,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,235,777,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,632,485,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,650,178,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,236,564,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,281,572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,928,546,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary profit (loss) | — | 
                                                282,710,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                167,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,092,338,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                957,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                873,484,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                969,012,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -329,125,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -305,224,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -369,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -342,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Profit (loss) attributable to owners of parent | — | 
                                                -1,349,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                883,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                921,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -415,810,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -648,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Comprehensive income | — | 
                                                -1,336,467,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                880,898,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                937,790,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -414,255,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -638,679,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net assets | 
                                                2,434,308,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,542,748,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,046,699,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,242,621,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,780,742,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,471,460,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,599,194,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,974,806,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,421,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,087,724,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                3,253,617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,235,684,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,759,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,762,868,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,265,837,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,132,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,465,387,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,768,334,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,540,415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,338,490,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | 
                                                281.68
                                                
                                             | — | — | 
                                                175.58
                                                
                                             | 
                                                476.14
                                                
                                             | 
                                                380.76
                                                
                                             | — | — | — | — | 
                                                317.59
                                                
                                             | 
                                                397.43
                                                
                                             | 
                                                299.03
                                                
                                             | — | 
                                                226.86
                                                
                                             | — | — | — | 
                                                279.92
                                                
                                             | 
                                                356.92
                                                
                                             | 
| Basic earnings (loss) per share | — | 
                                                -160.68
                                                
                                             | 
                                                -171.09
                                                
                                             | — | — | — | 
                                                103.40
                                                
                                             | 
                                                92.35
                                                
                                             | 
                                                99.13
                                                
                                             | 
                                                106.46
                                                
                                             | — | — | — | 
                                                -48.06
                                                
                                             | — | 
                                                -43.56
                                                
                                             | 
                                                -77.37
                                                
                                             | 
                                                -74.92
                                                
                                             | — | — | 
| Diluted earnings per share | — |  |  | — | — | — | 
                                                102.31
                                                
                                             | 
                                                91.37
                                                
                                             |  |  | — | — | — |  | — |  |  |  | — | — | 
| Equity-to-asset ratio | 
                                                0.728
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.660
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.843
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.853
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.841
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.832
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.347
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.290
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.284
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.331
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | 
                                                -0.423
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.613
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.237
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.265
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.364
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.306
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.147
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.172
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.239
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.188
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Price-earnings ratio | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                12.31
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13.79
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5.03
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4.69
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -29,411,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                634,823,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                168,902,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -281,363,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -192,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -657,262,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -511,427,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -429,836,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                33,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -20,112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -56,475,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -316,714,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,236,851,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,434,637,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                764,584,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                1,183,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,888,164,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                1,971,786,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,208,076,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                8,070,248,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Number of employees | 
                                                252
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                210
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                233
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                189
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                181
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                219
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                229
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                192
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                225
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                266
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                14
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                17
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |