Key Financial Data Of Group
| 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 group | ||||||||||||||||||||
| Business results of group | ||||||||||||||||||||
| Net sales | 
                                                105,157,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                119,532,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                113,270,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                105,534,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                102,904,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                109,983,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Operating revenue | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,853,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,575,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                7,189,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,244,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Ordinary profit (loss) | 
                                                7,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,602,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,975,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,827,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,960,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,569,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,585,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,447,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,482,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,175,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | 
                                                5,322,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                4,723,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,932,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,130,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,149,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | 
                                                7,949,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,986,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,625,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,276,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | 
                                                130,783,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                119,409,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                64,935,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                125,461,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                124,507,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,952,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,661,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                64,812,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                122,710,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                64,642,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | 
                                                177,679,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                163,527,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                99,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                176,045,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                171,924,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                95,619,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                167,126,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                95,391,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                171,160,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                95,126,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | 
                                                2,276.52
                                                
                                             | 
                                                2,078.28
                                                
                                             | — | 
                                                1,118.53
                                                
                                             | 
                                                2,189.40
                                                
                                             | — | — | — | 
                                                2,172.83
                                                
                                             | 
                                                1,118.83
                                                
                                             | 
                                                2,175.52
                                                
                                             | — | — | 
                                                1,116.42
                                                
                                             | — | 
                                                2,142.07
                                                
                                             | — | 
                                                1,113.61
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                923.33
                                                
                                             | 
                                                92.74
                                                
                                             | — | — | 
                                                51.78
                                                
                                             | — | — | 
                                                82.44
                                                
                                             | 
                                                67.51
                                                
                                             | 
                                                68.62
                                                
                                             | — | — | — | 
                                                77.80
                                                
                                             | 
                                                106.99
                                                
                                             | — | 
                                                77.11
                                                
                                             | — | 
                                                107.35
                                                
                                             | — | 
| Diluted earnings per share |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — |  | — |  | — | 
| Equity-to-asset ratio | — | — | 
                                                0.736
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.730
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.654
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.713
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.724
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.679
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.746
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.679
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.717
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.680
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | 
                                                0.575
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.042
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.046
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.038
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.060
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.032
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.070
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.050
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.069
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.050
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | 
                                                1.96
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                19.54
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                32.91
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                20.67
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                26.32
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                25.90
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                24.78
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                18.02
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                28.50
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                20.48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                1,549,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,008,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,346,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,189,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,739,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -3,187,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -6,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,560,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -4,259,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,943,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -3,347,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -3,363,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -4,112,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -4,918,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -5,117,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | 
                                                13,886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                18,816,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                26,289,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                26,476,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                30,509,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Number of employees | — | — | 
                                                2,042
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,353
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                117
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,138
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                2,222
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                115
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,243
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                114
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2,271
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                113
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |