Statement Of Changes In Equity
| Concept | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 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 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 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 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 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 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Statement of changes in equity | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Net assets | 
                                                -2,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                741,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                39,376,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                45,700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,616,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                875,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,960,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,607,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                47,317,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                39,376,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                130,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                33,054,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,707,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,586,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,735,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,933,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                802,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                671,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                33,054,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                261,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,865,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                535,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,512,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,098,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,745,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,666,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,037,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,037,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,998,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,998,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -274,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,007,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,666,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Changes during period | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dividends of surplus | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -2,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -2,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -2,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                -2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Profit (loss) | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                8,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                10,328,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,883,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,993,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                7,993,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,993,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                7,993,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,793,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disposal of treasury shares | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net changes in items other than shareholders' equity | — | — | — | — | 
                                                814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                203,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                611,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                404,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                135,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Total changes during period | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                68,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,253,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,322,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                203,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,322,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,767,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                611,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                8,582,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,699,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,253,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,841,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,187,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                404,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                135,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,098,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,644,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,841,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,641,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,098,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,728,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,644,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,098,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |