Consolidated Statement Of Cash Flows
| Concept | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-03-31 | As at 2022-09-30 | 2022-04-01 to 2022-09-30 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Profit (loss) before income taxes | — | 
                                                1,235,720,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                825,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | 
                                                165,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                151,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Amortization of goodwill | — | 
                                                11,907,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,055,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | — | 
                                                -725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                169,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | — | 
                                                -5,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,301,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest expenses | — | 
                                                3,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in retirement benefit liability | — | 
                                                -18,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,283,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in provision for bonuses | — | 
                                                52,168,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                62,244,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Share of loss (profit) of entities accounted for using equity method | — | 
                                                937,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -835,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | — | 
                                                925,203,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                511,133,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | — | 
                                                357,659,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                187,754,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -365,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -299,754,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | — | 
                                                -249,341,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -687,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | — | 
                                                -103,159,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                280,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                561,340,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                213,951,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -214,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -323,866,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                5,749,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loss (gain) on sale of non-current assets | — | 
                                                -389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,195,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -3,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,724,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Payments into time deposits | — | 
                                                -32,076,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -30,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from withdrawal of time deposits | — | 
                                                31,792,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                68,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of property, plant and equipment | — | 
                                                -94,578,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -346,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                1,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                58,985,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -1,542,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -255,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | — | 
                                                -1,496,092,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loan advances | — | 
                                                -25,079,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -578,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from collection of loans receivable | — | 
                                                15,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                227,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Dividends paid | — | 
                                                -236,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -219,883,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | — | 
                                                1,990,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -235,274,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -99,834,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid to non-controlling interests | — | 
                                                -150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Redemption of bonds | — | 
                                                -100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                1,265,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -22,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -2,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,307,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                26,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                68,277,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                311,842,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,576,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                2,611,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,299,921,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,338,962,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,335,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |