| 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 |