| SUMI LIMITED | Private company limited by shares | Dissolved |
| SUMI LIMITED | Private company limited by shares | Live |
| Sumi HK Limited | Private company limited by shares | Live |
| Sam Sumi Company Limited | | Live |
| SUMI ENTERPRISE LIMITED | Private company limited by shares | Dissolved |
| SUMI GORGEOUS LIMITED | Private company limited by shares | Live |
| SUMI WISDOM LIMITED | Private company limited by shares | Live |
| SUMIC GROUP LIMITED | Private company limited by shares | Live |
| SUMIC Technology (HK) Co., Limited | Private company limited by shares | Live |
| SUMIC (HONG KONG) CO., LIMITED | Private company limited by shares | Dissolved |
| Ataraxia Sumica Limited | | Live |
| SUMICO LIMITED | Private company limited by shares | Dissolved |
| SUMIDA LCM COMPANY LIMITED | Private company limited by shares | Dissolved |
| SUMIDA CORPORATE SERVICE COMPANY LIMITED | Private company limited by shares | Dissolved |
| SUMIDA ELECTRIC (H.K.) COMPANY LIMITED | Private company limited by shares | Live |
| SUMIDA ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| Hong Kong Sumida Trading Co., Limited | Private company limited by shares | Live |
| SUMIDA & ICHIRO YAWATA FOUNDATION LIMITED | Company limited by guarantee | Live |
| SUMIDA INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| SUMIDA OPT-ELECTRONICS COMPANY LIMITED | Private company limited by shares | Dissolved |
| SUMIDA PRECISION (H.K.) COMPANY LIMITED | Private company limited by shares | Dissolved |
| SUMIDA SERVICE COMPANY LIMITED | Private company limited by shares | Live |
| SUMIDA TRADING COMPANY LIMITED | Private company limited by shares | Live |
| SUMIDA ELECTRIC (VIETNAM) COMPANY LIMITED | Private company limited by shares | Dissolved |
| SUMIDA WITTIS ELECTRONICS COMPANY LIMITED | Private company limited by shares | Dissolved |
| SUMIDEN SHOJI (H.K.) CO., LIMITED | Private company limited by shares | Dissolved |
| SUMIDEN TRADING (HONG KONG) COMPANY LIMITED | Private company limited by shares | Dissolved |
| Sumiden International Trading (H.K.) Co., Limited | Private company limited by shares | Live |
| SUMIE IN ENGLISH LIMITED | Private company limited by shares | Live |
| HK Sumiec Limited | Private company limited by shares | Live |
| SUMIKA A&L HONG KONG LIMITED | Private company limited by shares | Dissolved |
| SUMIKA ELECTRONIC MATERIALS (HONGKONG) CO., LIMITED | Private company limited by shares | Live |
| Sumikko Limited | | Live |
| SUMILA COMPANY LIMITED | Private company limited by shares | Live |
| SUMIN LIMITED | Private company limited by shares | Dissolved |
| SUMING ENG. CO., LIMITED | Private company limited by shares | Dissolved |
| SUMING NEW ENERGY HONG KONG CO., LIMITED | Private company limited by shares | Live |
| Suming Industry Co., Limited | | Live |
| SUMING TECHNOLOGY LIMITED | Private company limited by shares | Live |
| SUMING TRADING CO., LIMITED | Private company limited by shares | Live |
| SUMINGLAND LIMITED | Private company limited by shares | Dissolved |
| Sumino Seiko Machinery Co., Limited | | Live |
| Sumino Holding Limited | | Live |
| Sumir Home Textiles And Furnishings Limited | Private company limited by shares | Live |
| SUMISEI LEASING (HONG KONG) CO., LIMITED | Private company limited by shares | Dissolved |
| SUMIT LIMITED | Private company limited by shares | Live |
| SumiTech Company Limited | Private company limited by shares | Dissolved |
| SUMITOMO LIMITED | Private company limited by shares | Dissolved |
| SUMITOMO ELECTRIC ASIA, LIMITED | Private company limited by shares | Live |
| SUMITON COMPANY LIMITED | Private company limited by shares | Dissolved |
| Sumitpo Limited | | Live |
| SUMITRA LIMITED | Private company limited by shares | Dissolved |
| SUMIXAM LIMITED | Private company limited by shares | Live |
| THE SUMIYAKI WAY LIMITED | | Live |