Statement Of Changes In Equity
| Concept | 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 | 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 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 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 | 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 | 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 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 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 | 
                                                26,835,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,966,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,858,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,833,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -89,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,119,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,966,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                25,481,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,393,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,421,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,376,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,376,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                25,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                27,857,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,396,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,726,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -262,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,917,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,179,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -262,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,726,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Changes during period | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dividends of surplus | — | — | — | — | — | — | — | 
                                                -1,709,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,709,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,709,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -1,709,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -301,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                25,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -301,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -301,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -326,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Profit (loss) | — | — | — | — | — | — | — | 
                                                2,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,997,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,997,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,997,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,997,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disposal of treasury shares | — | — | — | — | — | — | — | — | — | — | — | 
                                                917,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                917,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net changes in items other than shareholders' equity | — | — | — | — | — | — | — | — | — | — | 
                                                -2,092,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,092,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -2,092,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                2,638,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,638,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                2,638,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Total changes during period | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                436,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                436,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,092,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,092,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -738,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,695,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,638,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,301,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,393,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,638,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,670,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — |