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 | — | 
                                                108,547,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | 
                                                2,762,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,151,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | — | 
                                                12,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                97,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | — | 
                                                -75,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -24,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest expenses | — | 
                                                4,724,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,756,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in retirement benefit liability | — | 
                                                -190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,461,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | — | 
                                                159,054,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                346,256,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | — | 
                                                212,286,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                237,186,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -3,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | — | 
                                                -26,570,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -16,590,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                151,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                337,343,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | — | 
                                                -130,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                79,615,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -13,035,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -25,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                44,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                25,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -4,562,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -7,322,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Proceeds from withdrawal of time deposits | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of property, plant and equipment | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,318,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -11,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                126,881,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Proceeds from issuance of shares | — | 
                                                10,305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                99,044,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -21,344,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -14,471,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -46,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -54,646,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Redemption of bonds | — | 
                                                -32,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -219,355,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                32,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -79,225,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                496,299,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                1,104,667,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,183,893,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,463,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                967,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |