| SEIKO COMPANY LIMITED | Private company limited by shares | Live |
| JVS SEIKO LIMITED | Private company limited by shares | Live |
| VSU SEIKO LIMITED | Private company limited by shares | Live |
| JM SEIKO LIMITED | | Live |
| AOBA SEIKO CO. LIMITED | Private company limited by shares | Live |
| SEIKO CENTRE LIMITED | Private company limited by shares | Dissolved |
| SUNRISE SEIKO COMPANY LIMITED | | Live |
| TINON SEIKO COMPANY LIMITED | Private company limited by shares | Live |
| WELL-TRANS SEIKO COMPANY LIMITED | Private company limited by shares | Dissolved |
| SEIKOHOME COMPANY LIMITED | Private company limited by shares | Live |
| SEIKOM TRANSPORTATION LIMITED | Private company limited by shares | Dissolved |
| SEIKOM METAL WORKS LIMITED | Private company limited by shares | Dissolved |
| SEIKON LIMITED | Private company limited by shares | Dissolved |
| Seikonveyor Co., Limited | Private company limited by shares | Live |
| SEIKOO TRADING CO., LIMITED | | Live |
| CHINA SEIKOPACKING CO., LIMITED | Private company limited by shares | Live |
| SEIKO-SIGYO INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| SEIKOTECH COMPANY LIMITED | Private company limited by shares | Dissolved |
| DAIWA SEIKOU COMPANY LIMITED | Private company limited by shares | Dissolved |
| SEIKOU INDUSTRIAL CO., LIMITED | Private company limited by shares | Live |
| SeiKou Precision Machinery Limited | Private company limited by shares | Live |
| SEIKOU SHOJI COMPANY LIMITED | Private company limited by shares | Dissolved |
| KAWASAKI SEIKOUKI CO. LIMITED | Private company limited by shares | Live |
| SEIKO-VIP LIMITED | Private company limited by shares | Live |
| SeikoYamaha Power Industry & Trade Co., Limited | Private company limited by shares | Live |