Statement Of Changes In Equity
| Concept | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 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 | 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 | 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 | 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 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 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 | 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 | 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 | 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 | 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 | 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 | 
                                                -53,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,104,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                136,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,618,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,298,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,063,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -53,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,104,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                33,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                17,282,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,728,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,893,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                23,204,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,742,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -55,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,976,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                165,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,098,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,040,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,586,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,098,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,298,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -55,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,536,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,368,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                167,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,458,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                132,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                133,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,004,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,614,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                133,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,016,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,457,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                137,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,093,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,093,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -57,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -57,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,298,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,148,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,324,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                17,696,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Changes during period | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dividends of surplus | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -701,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Profit (loss) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                2,008,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,008,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,008,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                2,390,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,008,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,045,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disposal of treasury shares | — | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net changes in items other than shareholders' equity | — | — | — | 
                                                -29,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -26,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -26,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                28,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Total changes during period | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -29,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -26,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,313,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,283,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,695,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,668,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,687,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,306,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                972,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,351,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                980,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,001,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                972,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,344,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |