| Groovenauts Co., Ltd | Fukuoka |
| GrooveSign Co., Ltd | Kanagawa |
| Growth Verse Co., Ltd | Tokyo |
| Gulraj Trading Corporation | Osaka |
| Gumi Co., Ltd | Tokyo |
| GungHo Games | Tokyo |
| GungHo Online Entertainment, Inc. | Tokyo |
| Gunma Internet Co., Ltd | Gunma |
| Gunma Paz University | |
| Gunma Prefectural College of Health Sciences | |
| Gunma Prefectural Women's University | |
| Gunma University | |
| GVA Tech Co., Ltd | Tokyo |
| H.C. Networks Co., Ltd | Tokyo |
| Hacarus Co., Ltd | Kyoto |
| Hachinohe Institute of Technology | |
| Hagiwara Electric Holdings Co., Ltd | |
| Hagiwara Solutions Co., Ltd | |
| Hagoromo University | |
| Hakko Corporation | Osaka |
| Hakodate Otani Gakuen | |
| Hakodate University | |
| Hakuho College | |
| Hakuto Co., Ltd | Tokyo |
| Hamakko | Kanagawa |
| Hamamatsu Gakuin University | |
| Hamamatsu Photonics Co., Ltd | Shizuoka |
| Hamamatsu University School of Medicine | |
| HanaVax Co., Ltd | Chiba |
| HanaVax, Inc. | |
| Hanazono University | |
| HAND Co., Ltd | Tokyo |
| Hannan University | |
| Hanshin Electric Wire & Cable Co., Ltd | Tokyo |
| Happy Elements Co., Ltd | Kyoto |
| Happy Hacking Life | Tokyo |
| HappyHack Co., Ltd | Tokyo |
| HARADA Corporation | |
| Hardfocus International | Tokyo |
| Harmotec Corporation | Yamanashi |
| Hash DasH Co., Ltd | Tokyo |
| Hashilus Co., Ltd | Tokyo |
| Hatapro Co., Ltd | Kyoto |
| Hatena | Tokyo |
| Healios Co., Ltd | Tokyo |
| Health Media Co., Ltd | Tokyo |
| Health Science University | |
| Health Sciences University of Hokkaido | |
| Healthtech/SUM | Tokyo |
| Heart Square | Tokyo |