Key Financial Data Of Group
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-09-30 | 2022-04-01 to 2022-09-30 | As at 2022-09-30 | 2022-04-01 to 2022-09-30 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of group | ||||||||||||||||||||
| Business results of group | ||||||||||||||||||||
| Operating revenue | — | 
                                                36,073,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                36,269,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                16,759,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                31,709,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                16,133,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary income | — | — | 
                                                224,887,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                404,743,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                194,469,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                331,323,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                154,093,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                28,079,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,633,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                21,103,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,937,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                44,456,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,611,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                50,050,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,729,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                44,297,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | — | 
                                                39,180,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                61,178,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                30,287,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                31,152,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                30,760,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | — | 
                                                -2,454,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                135,900,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,707,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -15,678,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -59,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                1,007,378,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                584,927,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,021,746,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                567,644,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                567,718,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                897,596,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                567,713,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                901,750,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                586,487,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                868,205,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                32,923,058,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                761,303,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                32,649,727,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                749,306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                746,541,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                31,667,099,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                739,419,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,924,282,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                757,812,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                28,827,763,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets per share | 
                                                5,326.36
                                                
                                             | — | — | — | — | — | 
                                                5,397.27
                                                
                                             | — | — | — | — | 
                                                4,774.69
                                                
                                             | — | — | 
                                                4,796.99
                                                
                                             | — | — | — | 
                                                4,618.82
                                                
                                             | — | 
| Basic earnings (loss) per share | — | — | 
                                                207.23
                                                
                                             | — | — | 
                                                324.76
                                                
                                             | — | — | — | 
                                                161.35
                                                
                                             | — | — | — | — | — | 
                                                165.54
                                                
                                             | — | — | — | 
                                                163.04
                                                
                                             | 
| Diluted earnings per share | — | — |  | — | — |  | — | — | — |  | — | — | — | — | — |  | — | — | — |  | 
| Equity-to-asset ratio | 
                                                0.0305
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.7683
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0312
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.7575
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.7604
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.0283
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.7677
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.0300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.7739
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.0300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -408,511,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,480,879,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,052,962,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -111,261,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -834,877,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -486,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -790,090,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -443,723,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,082,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -256,823,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -10,819,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -20,726,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -9,847,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -23,732,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -13,856,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                7,539,505,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                8,445,177,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,307,918,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,708,412,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,734,834,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Number of employees | 
                                                8,254
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                317
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7,995
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                304
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                294
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                7,765
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                273
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7,546
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                314
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                7,850
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Average number of temporary employees | 
                                                2,654
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                51
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2,763
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                47
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                47
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2,733
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                42
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                2,754
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                41
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2,769
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — |