Statement Of Cash Flows
| Concept | 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 2023-03-31 | 
|---|---|---|---|---|---|
| Statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | — | 
                                                3,228,263,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,548,749,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | — | 
                                                112,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                101,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -398,053,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -283,526,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -2,858,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                2,940,306,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,365,961,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from operating activities | |||||
| Cash flows from operating activities | |||||
| Cash flows from facilities maintenance and investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -1,372,012,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,776,399,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                27,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | — | 
                                                -679,072,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -404,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of securities | — | 
                                                -200,130,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,701,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Loan advances | — | 
                                                -9,986,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,228,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from collection of loans receivable | — | 
                                                2,290,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,259,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                34,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,344,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Net cash provided by (used in) investing activities | — | 
                                                727,355,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,552,265,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | — | 
                                                -803,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | — | 
                                                -115,915,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -115,921,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -501,398,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -119,958,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                3,166,262,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,693,737,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                12,493,420,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,327,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,633,420,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |