Semi-Annual Consolidated Statement Of Cash Flows
| Concept | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|
| Semi-annual consolidated statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                1,487,401,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,972,669,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,742,724,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,465,945,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                1,463,262,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,402,966,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Impairment losses | — | — | 
                                                3,699,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                -891,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -169,224,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -191,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                61,981,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                48,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in retirement benefit liability | — | — | 
                                                -83,222,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -152,780,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Share of loss (profit) of entities accounted for using equity method | — | — | 
                                                -469,420,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -437,484,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Loss (gain) on sale of property, plant and equipment | — | — | 
                                                -179,678,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -16,130,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                -98,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -227,489,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                23,938,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,267,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                602,319,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -211,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                3,132,688,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,921,857,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                408,646,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                354,335,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -63,036,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -48,577,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -251,333,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -416,017,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                3,243,225,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,811,598,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Purchase of property, plant and equipment | — | — | 
                                                -2,210,618,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,058,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of property, plant and equipment | — | — | 
                                                240,343,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of investment securities | — | — | 
                                                -4,510,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -63,265,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                141,796,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from collection of loans receivable | — | — | 
                                                4,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                9,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -2,011,233,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,075,905,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Proceeds from short-term borrowings | — | — | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of short-term borrowings | — | — | 
                                                -500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                3,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -3,793,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,192,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of treasury shares | — | — | 
                                                -1,432,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,117,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -436,576,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -398,739,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -1,442,377,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -508,706,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | — | 
                                                77,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,123,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                -210,307,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,771,889,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                6,346,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,556,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,328,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |