| Hitachi Systems Ltd | Tokyo |
| Hitachi Zosen Corporation | |
| Hitomedia Co., Ltd | Tokyo |
| Hitotoki Incubator | Tokyo |
| Hitotsubashi University | Tokyo |
| HiTTO Co., Ltd | Tokyo |
| Hobsei Gokuen University | |
| Hokiruku University | |
| Hokkai School of Commerce | |
| Hokkai-Gakuen University | |
| Hokkaido Bunkyo University | |
| Hokkaido Research Organization | |
| Hokkaido University | |
| Hokkaido University - Department of Mathematics | Hokkaido |
| Hokkaido University - Graduate School of Information Science and Technology | Hokkaido |
| Hokkaido University - Research Institute for Electronic Sciences | Hokkaido |
| Hokkaido University of Education | |
| Hokkaido Venture Capital | |
| Hokkaido Venture Capital, Inc. | Hokkaido |
| Hokuriku Gakuin | |
| Hokusho University | |
| Hokuyo Automatic Co., Ltd | |
| HoloLab Co., Ltd | Tokyo |
| Holon Co., Ltd | Tokyo |
| Home Server Technical | Osaka |
| Honda Motor Co., Ltd | Tokyo |
| Honest Corporation | Tokyo |
| HORIBA Ltd | Kyoto |
| Horizon Data Works Co., Ltd | Tokyo |
| Hosei University | |
| Hoshi University | |
| Hosho Gakuen | |
| HospitalNet Co., Ltd | Tokyo |
| Hotline Co., Ltd | Tokyo |
| Housing Support Information Systems Co., Ltd | Tokyo |
| Hoyu Technology | Aichi |
| HPC Systems, Inc. | |
| HRBrain, Inc. | |
| Hugle Electronics Co., Ltd | Tokyo |
| HULINKS Co., Ltd | Tokyo |
| Human Interface Communications Co., Ltd | Tokyo |
| HUMAX Co., Ltd | Tokyo |
| Humble Bunny Kabushiki Kaisha | |
| Hunglead, Inc. | Tokyo |
| Hunters Co., Ltd | Tokyo |
| HunterSoft | Tokyo |
| Hutzper Co., Ltd | Osaka |
| Hyogo Cancer Center | |
| Hyogo Medical University | |
| Hyogo Social Welfare Corporation | |