Quarterly Consolidated Statement Of Cash Flows
| Concept | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Profit (loss) before income taxes | — | 
                                                99,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                363,569,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | 
                                                133,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                116,582,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | — | 
                                                -311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -168,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | — | 
                                                -120,906,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -102,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | — | 
                                                364,384,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                227,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | — | 
                                                -90,381,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -158,249,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | — | 
                                                1,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -40,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                8,245,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,424,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | — | 
                                                266,582,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                349,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                120,888,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                102,450,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -84,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -60,557,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                302,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                390,991,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -82,879,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -67,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,520,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                56,580,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -81,129,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -11,637,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | — | 
                                                -38,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -83,239,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -103,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -83,277,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -103,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                138,425,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                275,793,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                2,072,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,934,148,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,658,354,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |