| Mar 31,
2018 | Mar 31,
2019 | Mar 31,
2020 | Mar 31,
2021 | Mar 31,
2022 | Mar 31,
2023 | Mar 31,
2024 |
|---|
| Cash and deposits | - | 3,646 | 3,922 | 5,524 | 6,351 | 6,584 | 6,966 |
|---|
| Notes receivable - trade | - | 138 | 57 | 93 | 25 | 57 | 53 |
|---|
| Electronically recorded monetary claims - operating | - | 34 | 31 | 28 | - | 11 | 3 |
|---|
| Accounts receivable Trade and Contract Assets | - | - | - | - | 658 | 920 | 1,047 |
|---|
| Inventories | - | 82 | 100 | 135 | 107 | 99 | 91 |
|---|
| Advance payments to suppliers | - | 23 | 51 | 167 | 39 | 46 | 54 |
|---|
| Prepaid expenses | - | 183 | 183 | 167 | 418 | 458 | 440 |
|---|
| Other | - | 47 | 53 | 49 | 119 | 51 | 50 |
|---|
| Allowance for doubtful accounts | - | -35 | -49 | -19 | -7 | -9 | -12 |
|---|
| Current assets | - | 5,444 | 6,103 | 6,847 | 7,710 | 8,218 | 8,692 |
|---|
| Buildings, net | - | 953 | 914 | 877 | 841 | 835 | 815 |
|---|
| Structures, net | - | 10 | 9 | 8 | 7 | 6 | 6 |
|---|
| Machinery and equipment, net | - | 1 | 3 | 1 | 1 | 0 | - |
|---|
| Vehicles, net | - | 3 | 1 | 13 | 9 | 6 | 4 |
|---|
| Tools, furniture and fixtures, net | - | 1,825 | 2,032 | 2,076 | 2,138 | 1,673 | 1,493 |
|---|
| Land | - | 1,711 | 1,711 | 1,711 | 1,711 | 1,711 | 1,711 |
|---|
| Leased assets, net | - | 7 | 8 | 5 | 11 | 11 | 8 |
|---|
| Construction in progress | - | 34 | 34 | 28 | 24 | 31 | 19 |
|---|
| Property, plant and equipment | - | 4,542 | 4,712 | 4,719 | 4,740 | 4,274 | 4,056 |
|---|
| Software | - | 316 | 289 | 238 | 204 | 256 | 200 |
|---|
| Other | - | 11 | 11 | 11 | 11 | 11 | 11 |
|---|
| Intangible assets | - | 327 | 300 | 249 | 214 | 267 | 211 |
|---|
| Investment securities | - | 66 | 54 | 67 | 65 | 68 | 81 |
|---|
| Investments in capital | - | 1 | 1 | 1 | 1 | 1 | 1 |
|---|
| Long-term loans receivable | - | - | 0 | 0 | 0 | 0 | 1 |
|---|
| Distressed receivables | - | 70 | 72 | 71 | 85 | 84 | 84 |
|---|
| Long-term prepaid expenses | - | 120 | 120 | 131 | 133 | 156 | 208 |
|---|
| Insurance funds | - | 330 | 330 | 330 | 280 | 281 | 231 |
|---|
| Deferred tax assets | - | 219 | 236 | 234 | 182 | 304 | 324 |
|---|
| Other | - | 207 | 215 | 207 | 186 | 193 | 146 |
|---|
| Allowance for doubtful accounts | - | -76 | -78 | -77 | -85 | -84 | -84 |
|---|
| Investments and other assets | - | 937 | 950 | 964 | 848 | 1,004 | 992 |
|---|
| Non-current assets | - | 5,806 | 5,962 | 5,932 | 5,803 | 5,545 | 5,258 |
|---|
| Assets | - | 11,250 | 12,065 | 12,779 | 13,513 | 13,762 | 13,950 |
|---|
| Accounts payable - trade | - | 926 | 1,050 | 813 | 648 | 880 | 642 |
|---|
| Lease liabilities | - | 2 | 3 | 2 | 4 | 4 | 4 |
|---|
| Accounts payable - other | - | 317 | 229 | 167 | 167 | 198 | 192 |
|---|
| Accrued expenses | - | 231 | 262 | 276 | 299 | 269 | 264 |
|---|
| Income taxes payable | - | 200 | 260 | 487 | 56 | 122 | 181 |
|---|
| Accrued consumption taxes | - | 113 | 129 | 133 | 49 | 76 | 120 |
|---|
| Contract liabilities | - | - | - | - | 4,386 | 4,518 | 4,697 |
|---|
| Advances received | - | 556 | 564 | 603 | 5 | 3 | 3 |
|---|
| Deposits received | - | 28 | 27 | 23 | 25 | 25 | 25 |
|---|
| Provision for bonuses | - | 150 | 172 | 178 | 182 | 165 | 172 |
|---|
| Asset retirement obligations | - | 1 | 1 | 1 | 1 | 1 | 1 |
|---|
| Other | - | 16 | 23 | 83 | 1 | 0 | - |
|---|
| Current liabilities | - | 6,461 | 6,708 | 6,567 | 5,824 | 6,261 | 6,301 |
|---|
| Lease liabilities | - | 5 | 6 | 4 | 9 | 9 | 6 |
|---|
| Provision for retirement benefits | - | 62 | 59 | 71 | 80 | 92 | 114 |
|---|
| Provision for retirement benefits for directors (and other officers) | - | 69 | 73 | 77 | 80 | 75 | 80 |
|---|
| Asset retirement obligations | - | 12 | 12 | 13 | 13 | 15 | 16 |
|---|
| Other | - | 16 | 15 | 15 | 16 | 18 | 13 |
|---|
| Non-current liabilities | - | 222 | 183 | 180 | 197 | 209 | 229 |
|---|
| Liabilities | - | 6,683 | 6,891 | 6,747 | 6,022 | 6,470 | 6,530 |
|---|
| Share capital | - | 153 | 153 | 153 | 924 | 924 | 924 |
|---|
| Legal capital surplus | - | 0 | 0 | 0 | 771 | 771 | 771 |
|---|
| Capital surplus | - | 0 | 0 | 0 | 771 | 771 | 771 |
|---|
| Legal retained earnings | - | 38 | 38 | 38 | 38 | 38 | 38 |
|---|
| Other general reserve | - | 50 | 50 | 50 | 50 | 50 | 50 |
|---|
| General reserve | - | 704 | 704 | 704 | 704 | 704 | 704 |
|---|
| Retained earnings brought forward | - | 3,599 | 4,211 | 5,060 | 4,979 | 4,778 | 4,897 |
|---|
| Retained earnings | - | 4,390 | 5,003 | 5,851 | 5,771 | 5,570 | 5,689 |
|---|
| Treasury shares | - | - | - | - | -0 | -0 | -0 |
|---|
| Shareholders' equity | - | 4,544 | 5,156 | 6,005 | 7,465 | 7,264 | 7,383 |
|---|
| Valuation difference on available-for-sale securities | - | 24 | 17 | 27 | 26 | 28 | 37 |
|---|
| Valuation and translation adjustments | - | 24 | 17 | 27 | 26 | 28 | 37 |
|---|
| Net assets | 3,942 | 4,567 | 5,174 | 6,032 | 7,491 | 7,292 | 7,420 |
|---|
| Liabilities and net assets | - | 11,250 | 12,065 | 12,779 | 13,513 | 13,762 | 13,950 |
|---|