| Saitama Medical University | |
| Saitama Prefectural University | |
| Saitama University | |
| Saitama University - Department of Information and Computer Sciences | Saitama |
| Saitama University - Department of Mathematics | Saitama |
| Saku University | |
| SAKURA Internet Co., Ltd | Osaka |
| Sakura Mobile | Tokyo |
| Sakura Sohgyo Co., Ltd | Tokyo |
| Sakushin Gakuin University | |
| Sales Robotics Co., Ltd | Tokyo |
| Saleshub Co., Ltd | Tokyo |
| Salesian Polytechnic | |
| Samurai Incubate, Inc. | |
| Samurai International Co., Ltd | Tokyo |
| San-ei Tsushin Kougyo Ltd | Saitama |
| SanBio Co., Ltd | Tokyo |
| Sancoh | Hokkaido |
| Sanei Co., Ltd | Saitama |
| Sanesu Denki Co., Ltd | Tokyo |
| Sangyko | Kanagawa |
| Saniku Gakuin College | |
| Sanka Network Co., Ltd | Tokyo |
| Sankan Electric Co., Ltd | Tokyo |
| Sanki-Tech Co., Ltd | Tokyo |
| Sanko System Co., Ltd | Tokyo |
| Sanko Telecom Co., Ltd | Tokyo |
| Sankyo Seisakusho Co. | |
| Sanmei Electronics Co., Ltd | |
| SANNO University | Tokyo |
| Sano Nihon University College | |
| Sanritz Automation Co., Ltd | Tokyo |
| Santen Pharmaceutical Co., Ltd | |
| Sanwa Kagaku Kenkyusho Co., Ltd | |
| Sanwa Supply | Tokyo |
| SANWA Technologies Co., Ltd | |
| Sanwell Co., Ltd | Tokyo |
| Sanyo Denki Co., Ltd | Tokyo |
| Sanyo Denki Co., Ltd | |
| Sanyo Gakuen University & College | |
| Sanyo Women's College | |
| Sanyo-Onoda City University | |
| Sapporo Gakuin University | |
| Sapporo International University | |
| Sapporo Medical University | |
| Sapporo Otani University & Junior College of Sapporo Otani University | |
| Sapporo University | |
| Satellite Network, Inc. | Tokyo |
| Sato Pharmaceutical Co., Ltd | |
| Satori Co., Ltd | Tokyo |