| Seisa University | |
| Seisen Jogakuin College | |
| Seisen University | |
| Seiwa Boeki Co., Ltd | Tokyo |
| Seiwa Gakuen College | |
| Seiwa Optical Co., Ltd | Tokyo |
| Seiwa University | |
| Semiconductor Equipment Association of Japan | Tokyo |
| SEMITEC Corporation | Tokyo |
| Sendai CATV Co., Ltd | Miyagi |
| Sendai Shirayuri Women's College | |
| Sendai University | |
| Senju Pharmaceutical Co., Ltd | |
| Senri Kinran University | |
| Senshu Electric Co., Ltd | Tokyo |
| Senshu University | Tokyo |
| Sensy Co., Ltd | Tokyo |
| Senzoku Gakuen | |
| Septeni Co., Ltd | Tokyo |
| SeqOnce Biosciences | |
| SerialGames Co., Ltd | Tokyo |
| Setsunan University | |
| Sevenwoods Investment | |
| SFiDA, Inc. | |
| SFM Co., Ltd | Tokyo |
| SG Incubate, Inc. | |
| SGcapital, Inc. | |
| Shaft Co., Ltd | Tokyo |
| Shanon Co., Ltd | Tokyo |
| Shared Systems Co., Ltd | Tokyo |
| Sharing Innovations Co., Ltd | Tokyo |
| Sharp Corporation | Osaka |
| Shibasoku Co., Ltd | Tokyo |
| Shibaura Institute of Technology | |
| Shibaura Mechatronics Corporation | Kanagawa |
| Shibuya Perl Mongers | Tokyo |
| Shibuya Startup Support | Tokyo |
| Shift, Inc. | Tokyo |
| Shiga Bunkyo Junior College | |
| Shiga University | |
| Shiga University of Medical Science | |
| Shiga Yamashita Co., Ltd | |
| Shigakkan University | |
| Shigakukan University | |
| Shijonawate Gakuen | |
| Shikoku Gakuin University | |
| Shikoku University | |
| Shimadzu Corporation | |
| Shimane Information Processing Center | |
| Shimane University | |