Statement Of Cash Flows
| Concept | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|
| Statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                -601,417,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -445,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                39,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,064,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -41,129,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -30,227,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -57,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -138,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from operating activities | |||||
| Net cash provided by (used in) operating activities | 
                                                -632,105,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -578,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from operating activities | |||||
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -839,456,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -648,835,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                6,017,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,100,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -759,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,293,342,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -1,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from facilities maintenance and investing activities | |||||
| Cash flows from financing activities | |||||
| Repayments of long-term borrowings | 
                                                -261,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -191,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                1,708,156,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                625,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                244,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                316,858,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,246,843,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                577,162,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                260,304,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,506,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |