Key Financial Data Of Group
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 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 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | |||||||||||||||||||||||
| Business results of group | |||||||||||||||||||||||
| Operating revenue | — | — | — | 
                                                37,766,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,965,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,597,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                77,698,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,911,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                61,566,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                999,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                57,755,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | — | — | — | 
                                                15,122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,332,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                292,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,775,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,273,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                25,693,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,173,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,723,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | — | — | — | 
                                                12,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                9,463,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                11,372,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -3,015,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | — | — | — | 
                                                14,585,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                14,370,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                16,399,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,947,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,942,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | — | 
                                                86,701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                46,956,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                72,416,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                43,600,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                43,484,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                81,411,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                74,427,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,348,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                71,343,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                27,305,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | — | 
                                                115,334,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                47,856,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                98,774,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                44,505,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                47,858,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                621,727,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                577,449,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                499,591,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                27,448,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | — | — | 
                                                2,869.94
                                                
                                             | — | — | 
                                                1,560.22
                                                
                                             | — | — | — | 
                                                2,388.07
                                                
                                             | 
                                                1,448.70
                                                
                                             | — | 
                                                1,391.56
                                                
                                             | 
                                                1,908.27
                                                
                                             | — | — | — | 
                                                1,681.34
                                                
                                             | 
                                                971.18
                                                
                                             | 
                                                1,376.79
                                                
                                             | — | — | 
                                                688.76
                                                
                                             | 
| Basic earnings (loss) per share | — | — | — | 
                                                402.07
                                                
                                             | — | — | 
                                                162.98
                                                
                                             | 
                                                5.98
                                                
                                             | 
                                                310.67
                                                
                                             | — | — | 
                                                438.77
                                                
                                             | — | — | 
                                                363.94
                                                
                                             | 
                                                340.58
                                                
                                             | 
                                                169.53
                                                
                                             | — | — | — | 
                                                2.68
                                                
                                             | 
                                                -76.06
                                                
                                             | — | 
| Diluted earnings per share | — | — | — |  | — | — |  |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | — | — | 
                                                0.749
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.981
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.728
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.980
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.909
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.096
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.091
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.975
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.109
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.995
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | — | — | 
                                                0.153
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.108
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.004
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.144
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.371
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.203
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.433
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.122
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.004
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.053
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | — | — | 
                                                2.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                5.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                166.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2.2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                3.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                282.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | — | 
                                                4,532,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -25,586,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                18,505,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -4,785,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                77,637,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | — | — | 
                                                -6,054,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -8,104,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -17,938,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -7,656,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -8,704,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | — | — | 
                                                -287,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                12,129,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,578,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,719,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -14,749,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | — | 
                                                17,137,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                18,199,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                186,057,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                191,071,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                185,412,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                198
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                588
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                385
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                530
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,372
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                5,148
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                5,320
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                76
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                67
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                48
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                12
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |