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 | 
                                                571,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                424,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -26,367,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -8,040,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -18,884,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -18,070,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                537,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                483,297,000
                                                
                                                    
                                                        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 | 
                                                -311,038,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -289,847,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                23,755,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | 
                                                -60,792,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -30,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -53,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -36,196,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||
| Net cash provided by (used in) investing activities | 
                                                -417,901,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -340,923,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||
| Proceeds from issuance of shares | 
                                                638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                235,964,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | 
                                                1,180,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,395,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | 
                                                -894,153,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,683,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                269,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -53,239,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -16,714,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -756,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                388,889,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                89,133,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                1,471,066,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,082,176,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                993,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |