Consolidated 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 | 
|---|---|---|---|---|---|
| Consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | — | 
                                                2,176,468,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,665,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | — | 
                                                5,751,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,973,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -34,511,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -26,657,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -711,771,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -291,951,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                1,485,125,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,588,751,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -491,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -583,841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                2,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -492,203,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -583,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | — | 
                                                -226,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from collection of loans receivable | — | 
                                                681,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                -884,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,781,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | — | 
                                                -132,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | — | 
                                                -232,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -174,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | — | 
                                                680,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | — | 
                                                -685,797,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -792,595,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -1,037,119,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,491,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -44,197,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -485,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                1,369,452,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,413,649,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,899,577,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |