Statement Of Cash Flows
| Concept | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | 
                                                32,078,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                291,745,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                10,053,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,675,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -17,529,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -7,244,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -889,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                23,712,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                292,176,000
                                                
                                                    
                                                        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 | 
                                                -119,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -30,213,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                116,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Net cash provided by (used in) investing activities | 
                                                -122,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -31,232,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Repayments of borrowings | 
                                                -4,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of treasury shares | 
                                                -863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -21,225,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -15,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -70,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -49,238,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -169,923,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                211,705,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                867,345,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,037,268,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,174,186,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                962,481,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |