| Company Name | Type | Status |
|---|---|---|
| KOYAMA COMPANY LIMITED | Private company limited by shares | Dissolved |
| KOYAMA ASIA CO., LIMITED | Private company limited by shares | Live |
| HONG KONG KOYAMA CO., LIMITED | Private company limited by shares | Live |
| KOYAMA INTERNATIONAL (HONGKONG) CO., LIMITED | Private company limited by shares | Live |
| KOYAMA TRADING INTERNATIONAL LIMITED | Private company limited by shares | Live |
| KOYAMACHI LIMITED | Private company limited by shares | Dissolved |
| KOYAMAEN LIMITED | Private company limited by shares | Live |