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 | — | 
                                                2,932,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | — | 
                                                145,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -510,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -314,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -93,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -77,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                2,492,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,685,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -3,074,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,733,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -3,108,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,688,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Dividends paid | — | 
                                                -85,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -51,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | — | 
                                                2,480,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | — | 
                                                -2,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,681,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                619,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -622,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                245,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                311,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                249,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -312,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                3,298,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,571,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |