| Wago Company of Japan Ltd | |
| Wakasa Wan Energy Research Center | |
| Wakayama Medical University | |
| Wakayama University | Wakayama |
| Wako University | |
| Wakunaga Pharmaceutical Co., Ltd | |
| Wakwak | Tokyo |
| Walbrix Corporation | Tokyo |
| Wamnet Japan Co., Ltd | Tokyo |
| Wamw Co., Ltd | Tokyo |
| WARK Co., Ltd | Tokyo |
| Wasabi Communications | Tokyo |
| Waseda University | |
| Watakei Co., Ltd | Tokyo |
| Way Way Engine Co., Ltd | Tokyo |
| Wayo Women's University | |
| WBZ.jp | Tokyo |
| WealthPark Co., Ltd | Tokyo |
| WeatlhNavi Co., Ltd | Tokyo |
| Web Analytics Consultants Association | |
| Web Base Co. | Tokyo |
| Web Factory Corporation | Tokyo |
| Web Frontier | Osaka |
| Web Jingle | Yamagata |
| Web Shizuoka | Shizuoka |
| Web Technology Corporation | Tokyo |
| Web Tokai Co., Ltd | Aichi |
| Web-Habu | Nagasaki |
| WEB-SHARK, Inc. | Osaka |
| WebARENA | Tokyo |
| Webedge Co., Ltd | Tokyo |
| Webeyes | Tokyo |
| Weblife Co., Ltd | Tokyo |
| WebMonkey Corporation | Tokyo |
| Weboss Co., Ltd | Hokkaido |
| WebSmart Co., Ltd | Tokyo |
| Webthor Co., Ltd | Tokyo |
| Webzen Japan Co., Ltd | Tokyo |
| WeCode-inc | |
| Weekday Co., Ltd | Tokyo |
| Weid Co., Ltd | Tokyo |
| Wellnet Corporation | Hokkaido |
| WellThera Co., Ltd | Tokyo |
| Weru Investment Co., Ltd | Tokyo |
| wesionaryTEAM Co., Ltd | Tokyo |
| WHOIS Corporation | Tokyo |
| Wicresoft Co., Ltd | Tokyo |
| WIDE Project | |
| Will Media Co., Ltd | Tokyo |
| Windabaft Co., Ltd | Tokyo |