Key Financial Data Of Reporting Company
| Concept | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 2019-04-01 to 2020-03-31 | As at 2020-03-31 | 2019-04-01 to 2020-03-31 | As at 2020-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||||||||||||||
| Business results of reporting company | ||||||||||||||||||||
| Net sales | 
                                                176,292,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                222,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                171,582,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                211,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                158,233,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                195,700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                151,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                187,509,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                149,995,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                186,349,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                11,207,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,780,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,548,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                17,328,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,531,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,703,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                13,873,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,381,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                12,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                16,274,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | 
                                                8,160,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                9,543,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                13,236,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                9,471,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,710,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Share capital | — | — | — | 
                                                13,150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                13,150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                13,150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                13,150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | — | 
                                                84,568,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                84,568,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                84,568,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                84,568,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                44,284,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | — | — | 
                                                145,844,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                115,478,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                113,660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                140,171,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                132,455,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                108,133,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,980,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                98,633,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                119,301,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                95,899,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | 
                                                298,580,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                270,851,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                272,921,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                298,623,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                262,695,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                238,616,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                247,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                223,343,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                242,497,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                220,479,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | 
                                                1,795.71
                                                
                                             | 
                                                1,428.80
                                                
                                             | — | 
                                                1,388.68
                                                
                                             | 
                                                1,703.56
                                                
                                             | — | — | — | 
                                                1,610.11
                                                
                                             | 
                                                1,321.39
                                                
                                             | 
                                                1,520.06
                                                
                                             | — | — | 
                                                1,205.71
                                                
                                             | — | 
                                                1,436.07
                                                
                                             | — | 
                                                1,159.89
                                                
                                             | 
| Dividend paid per share | 
                                                57.00
                                                
                                             | — | — | — | 
                                                47.00
                                                
                                             | — | — | — | 
                                                47.00
                                                
                                             | — | — | — | — | 
                                                65.00
                                                
                                             | — | — | 
                                                81.00
                                                
                                             | — | — | — | 
| Interim dividend paid per share | 
                                                21.50
                                                
                                             | — | — | — | 
                                                21.50
                                                
                                             | — | — | — | 
                                                21.50
                                                
                                             | — | — | — | — | 
                                                41.00
                                                
                                             | — | — | 
                                                40.00
                                                
                                             | — | — | — | 
| Basic earnings (loss) per share | 
                                                99.87
                                                
                                             | 
                                                143.50
                                                
                                             | — | — | 
                                                116.60
                                                
                                             | — | — | 
                                                140.87
                                                
                                             | 
                                                161.77
                                                
                                             | 
                                                136.96
                                                
                                             | — | — | — | 
                                                114.63
                                                
                                             | 
                                                147.80
                                                
                                             | — | 
                                                105.36
                                                
                                             | — | 
                                                130.36
                                                
                                             | — | 
| Diluted earnings per share |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | — | 
                                                0.486
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.426
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.416
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.467
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.502
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.453
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.503
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.442
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.490
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.435
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | 
                                                0.071
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.082
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.086
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.085
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.128
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.088
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.097
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.100
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.093
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.094
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | 
                                                27.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                28.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                23.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                21.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                39.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                30.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                34.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                27.5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | 
                                                0.571
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.403
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.291
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.388
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.384
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                29,176,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                20,071,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                23,148,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                31,814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                27,770,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -10,711,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -34,306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -22,866,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -19,131,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -10,989,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -17,013,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                16,745,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,578,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -15,086,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -15,643,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | 
                                                23,707,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                22,255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,745,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                17,884,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                20,288,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | — | — | 
                                                5,104
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                984
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                979
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,876
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                4,792
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                962
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                4,753
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                944
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                4,484
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                885
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | — | — | 
                                                439
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Total shareholder return | — | — | — | 
                                                0.915
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.058
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                0.932
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.404
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | — | — | 
                                                1.739
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.259
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.223
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.228
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.882
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |