Key Financial Data Of Reporting Company
| Concept | 2023-06-01 to 2024-05-31 | As at 2024-05-31 | 2023-06-01 to 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2024-05-31 | As at 2023-05-31 | As at 2023-05-31 | 2022-06-01 to 2023-05-31 | 2022-06-01 to 2023-05-31 | 2021-06-01 to 2022-05-31 | 2021-06-01 to 2022-05-31 | As at 2022-05-31 | As at 2022-05-31 | 2020-06-01 to 2021-05-31 | As at 2021-05-31 | 2020-06-01 to 2021-05-31 | As at 2021-05-31 | 2019-06-01 to 2020-05-31 | As at 2020-05-31 | As at 2020-05-31 | 2019-06-01 to 2020-05-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||||||||||||||||||||
| Business results of reporting company | ||||||||||||||||||||||||||
| Net sales | 
                                                135,701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                114,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                154,202,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                136,243,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                126,790,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                113,075,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                117,803,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                102,246,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                118,529,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                107,937,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | 
                                                -9,343,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -10,706,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                4,639,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,103,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,413,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,585,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,783,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,889,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) | — | — | 
                                                -8,320,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                3,191,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,811,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,797,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                7,345,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | — | 
                                                5,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                5,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,012,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total number of issued shares | — | 
                                                93,255,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                93,255,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                98,255,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                98,255,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                98,255,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | 
| Net assets | — | 
                                                62,335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                68,591,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                78,029,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                73,261,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                79,946,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                74,619,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                74,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                68,781,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                64,357,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,317,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | — | 
                                                120,088,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                145,677,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                162,339,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                141,471,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                154,724,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                133,497,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                148,766,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                123,319,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                118,533,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                133,937,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets per share | — | 
                                                746.35
                                                
                                             | — | — | — | — | 
                                                819.47
                                                
                                             | — | — | — | 
                                                935.11
                                                
                                             | 
                                                879.61
                                                
                                             | — | — | — | — | 
                                                900.89
                                                
                                             | 
                                                849.34
                                                
                                             | — | 
                                                846.77
                                                
                                             | — | 
                                                788.87
                                                
                                             | — | 
                                                738.53
                                                
                                             | 
                                                780.35
                                                
                                             | — | 
| Dividend paid per share | — | — | 
                                                22.00
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                26.00
                                                
                                             | — | 
                                                26.00
                                                
                                             | — | — | — | — | 
                                                26.00
                                                
                                             | — | — | — | — | 
                                                28.00
                                                
                                             | 
| Interim dividend paid per share | — | — | 
                                                10.00
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                10.00
                                                
                                             | — | 
                                                10.00
                                                
                                             | — | — | — | — | 
                                                10.00
                                                
                                             | — | — | — | — | 
                                                10.00
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                -86.21
                                                
                                             | — | 
                                                -99.76
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                38.95
                                                
                                             | 
                                                37.76
                                                
                                             | 
                                                84.47
                                                
                                             | 
                                                89.30
                                                
                                             | — | — | 
                                                88.92
                                                
                                             | — | 
                                                78.36
                                                
                                             | — | 
                                                91.37
                                                
                                             | — | — | 
                                                84.37
                                                
                                             | 
| Diluted earnings per share |  | — |  | — | — | — | — | — | — | — | — | — | 
                                                38.89
                                                
                                             | 
                                                37.70
                                                
                                             | 
                                                84.28
                                                
                                             | 
                                                89.09
                                                
                                             | — | — | 
                                                88.55
                                                
                                             | — | 
                                                78.03
                                                
                                             | — | 
                                                91.00
                                                
                                             | — | — | 
                                                84.03
                                                
                                             | 
| Equity-to-asset ratio | — | 
                                                0.519
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.470
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.480
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.518
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.512
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.559
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.496
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.558
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.543
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.508
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Rate of return on equity | 
                                                -0.098
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                -0.123
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0.042
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.043
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.097
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.102
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.121
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.117
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Price-earnings ratio | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                14.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                15.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                7.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                6.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                6.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Payout ratio | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                0.689
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.332
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.332
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                -1,263,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -11,062,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,759,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,572,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -3,476,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | 
                                                1,471,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -6,314,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,331,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,172,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -5,634,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -2,092,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -6,121,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -8,082,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                16,910,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,478,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | — | — | — | — | — | 
                                                21,947,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                23,749,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                47,170,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                46,954,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                27,522,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Number of employees | — | 
                                                830
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                36
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                290
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                450
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,048
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                504
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                36
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                562
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,094
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                863
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                1,106
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                884
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1,075
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                871
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                859
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,003
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Average number of temporary employees | — | 
                                                177
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                82
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                172
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                304
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                89
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                126
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                307
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                187
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                182
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                329
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                220
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                191
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                299
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Total shareholder return | — | 
                                                0.992
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1.137
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.988
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.035
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.970
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Total return on share price index | — | 
                                                2.070
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1.554
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.358
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.333
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.062
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |