Quarterly 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 | 
|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | — | 
                                                970,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                475,687,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | — | 
                                                67,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -23,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -15,598,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -117,516,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -128,612,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                896,171,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                386,892,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -378,285,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -757,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                22,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                90,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | — | 
                                                -7,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of investment securities | — | 
                                                1,038,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                117,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                -2,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                640,144,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -680,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Proceeds from short-term borrowings | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of short-term borrowings | — | 
                                                -200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | — | 
                                                1,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | — | 
                                                -1,012,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,016,091,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of treasury shares | — | 
                                                -45,218,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -14,421,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | — | 
                                                -94,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -94,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid to non-controlling interests | — | 
                                                -19,417,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -277,147,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                269,956,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                1,259,167,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -23,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                1,896,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                637,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                660,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |