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 | — | 
                                                1,130,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | — | 
                                                66,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -11,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -168,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -178,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                1,017,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                289,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from operating activities | |||||
| Cash flows from operating activities | |||||
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -239,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -183,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | — | 
                                                -35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -66,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -205,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -192,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of investment securities | — | 
                                                71,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                123,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from facilities maintenance and investing activities | |||||
| Cash flows from financing activities | |||||
| Purchase of treasury shares | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | — | 
                                                -57,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -48,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | — | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -833,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -66,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | — | 
                                                -349,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -298,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -22,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                277,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                299,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                269,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |