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 | — | 
                                                -195,001,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                94,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | 
                                                64,441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                47,348,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Amortization of goodwill | — | 
                                                25,441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | — | 
                                                -4,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                375,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | — | 
                                                -348,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -147,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest expenses | — | 
                                                18,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                24,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in provision for bonuses | — | 
                                                2,353,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                44,923,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loss (gain) on sale of property, plant and equipment | — | 
                                                -74,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | — | 
                                                -155,344,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -172,520,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | — | 
                                                -444,955,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -520,077,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | — | 
                                                -267,707,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -492,186,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -57,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -55,566,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | — | 
                                                87,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                234,518,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -421,145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -365,546,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -275,070,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                55,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -18,390,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -24,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Payments into time deposits | — | 
                                                -2,040,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of property, plant and equipment | — | 
                                                -73,968,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -109,795,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                74,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -174,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -129,107,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | — | 
                                                -80,382,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -18,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -9,812,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Dividends paid | — | 
                                                -49,647,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -82,924,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -241,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -260,145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Redemption of bonds | — | 
                                                -7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries not resulting in change in scope of consolidation | — | 
                                                -8,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                378,836,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -46,774,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of lease liabilities | — | 
                                                -8,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -8,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                -4,150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,742,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -221,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -538,686,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                2,244,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,466,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,920,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,459,447,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |