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 | 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 | 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 | 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 | 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 | As at 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 | 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 | As at 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 | 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 | 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 | 
                                                -559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                39,565,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                844,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,853,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,885,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                44,650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                60,039,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,271,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -704,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                38,720,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,447,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                59,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,447,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                69,195,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                44,650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                584,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                42,680,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                844,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,143,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                4,790,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,848,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                56,372,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                42,065,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -3,287,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                61,930,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,130,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,799,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                424,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                42,680,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,218,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                405,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,315,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,590,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,847,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                42,065,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,350,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,205,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                222,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,533,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                844,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,619,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Changes during period | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dividends of surplus | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -1,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -1,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -792,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Profit (loss) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                3,163,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,163,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,163,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                5,101,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,163,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                2,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                2,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                7,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disposal of treasury shares | — | — | — | — | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                48,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                48,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                84,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                84,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                84,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                84,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net changes in items other than shareholders' equity | — | — | — | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -528,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                3,885,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -424,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -167,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                3,356,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                362,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                581,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                581,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Total changes during period | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -528,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,583,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,583,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,885,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,887,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,970,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -424,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,970,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,908,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -167,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                7,265,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,173,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,887,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,848,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,673,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,815,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                362,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,735,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,735,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                581,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,673,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,752,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,396,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |