Statement Of Cash Flows
| Concept | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 2022-04-01 to 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 | |||||||
| Profit (loss) before income taxes | 
                                                967,425,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,580,790,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,226,772,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,166,684,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | 
                                                1,424,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,376,475,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | 
                                                220,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                70,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | 
                                                -59,680,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -44,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest expenses | 
                                                45,713,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                20,265,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | 
                                                -7,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -250,293,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in accounts payable - other | 
                                                -367,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                435,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -103,467,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -272,464,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | 
                                                221,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,779,015,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                59,680,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                44,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -45,964,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -21,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -342,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -328,252,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from operating activities | |||||||
| Loss (gain) on sale of property, plant and equipment | 
                                                -199,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -3,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in provision for bonuses | 
                                                73,151,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -46,589,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | 
                                                -1,984,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -259,820,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | 
                                                -355,735,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                426,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                -271,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,474,554,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from operating activities | |||||||
| Loss (gain) on sale of investment securities | 
                                                -10,841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from facilities maintenance and investing activities | |||||||
| Purchase of property, plant and equipment | 
                                                -1,541,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -818,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,143,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | 
                                                -1,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,684,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | 
                                                11,841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loan advances | 
                                                -514,510,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -685,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -22,231,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -8,790,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||||
| Net cash provided by (used in) investing activities | 
                                                -2,086,189,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,417,951,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||||
| Proceeds from short-term borrowings | 
                                                1,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of short-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | 
                                                -3,599,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -47,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | 
                                                -240,749,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -313,466,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from issuance of bonds | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -2,547,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,179,605,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | 
                                                -200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -2,129,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                90,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                58,342,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -4,814,719,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,294,551,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                4,531,361,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,346,080,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,051,529,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |