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 | — | 
                                                -137,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,612,123,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | — | 
                                                150,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                115,104,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -408,818,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -198,388,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -99,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -71,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -413,957,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,523,197,000
                                                
                                                    
                                                        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 | — | 
                                                -929,076,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -612,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                45,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | — | 
                                                -23,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,450,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of investment securities | — | 
                                                27,031,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                793,027,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                -24,354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,691,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Net cash provided by (used in) investing activities | — | 
                                                78,619,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                191,685,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | — | 
                                                -121,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | — | 
                                                -156,962,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -156,976,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | — | 
                                                1,550,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                973,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | — | 
                                                -1,578,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,237,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                743,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -896,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                212,218,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,209,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                620,046,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                876,322,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                3,840,963,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,220,917,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,344,595,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |