Consolidated Statement Of Cash Flows
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Profit (loss) before income taxes | — | 
                                                797,052,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                895,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | 
                                                672,707,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                655,250,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | — | 
                                                -180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -16,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | — | 
                                                -266,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -251,718,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest expenses | — | 
                                                7,867,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                11,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in provision for bonuses | — | 
                                                -591,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,553,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Foreign exchange losses (gains) | — | 
                                                16,912,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -24,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in retirement benefit liability | — | 
                                                78,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                44,769,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Share of loss (profit) of entities accounted for using equity method | — | 
                                                59,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                57,517,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loss (gain) on sale of securities | — | 
                                                -26,013,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | — | 
                                                1,900,071,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                965,889,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | — | 
                                                511,718,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                152,561,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | — | 
                                                -726,349,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -201,771,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                1,804,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                946,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | — | 
                                                1,063,784,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -206,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -4,188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                266,805,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                252,038,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -8,237,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -11,741,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Payments into time deposits | — | 
                                                -3,400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from withdrawal of time deposits | — | 
                                                3,400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of property, plant and equipment | — | 
                                                -481,864,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -545,135,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                522,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                33,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -2,902,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -564,880,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -574,523,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | — | 
                                                28,547,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,420,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loan advances | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -6,490,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from collection of loans receivable | — | 
                                                100,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Purchase of treasury shares | — | 
                                                -109,886,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -105,062,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in short-term borrowings | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -700,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -285,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -290,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid to non-controlling interests | — | 
                                                -29,454,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -29,454,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -780,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -620,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -1,204,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,445,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of lease liabilities | — | 
                                                -376,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -376,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                6,602,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,705,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                41,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,066,812,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                8,697,326,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,655,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,721,381,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,788,194,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |