| Innotech Corporation | Tokyo |
| Innova Co., Ltd | Tokyo |
| Innovation Engine, Inc. | |
| INQ Co., Ltd | Tokyo |
| Insight Core Co., Ltd | Tokyo |
| Insight Plus Co., Ltd | Tokyo |
| Insight Technology | Tokyo |
| Institute for Future Engineering | |
| Institute of Advanced Media Arts and Sciences | |
| Institute of Applied Energy | |
| Institute of Behavioral Sciences | |
| Institute of Brain and Blood Vessels | |
| Institute of Developing Economies | |
| Institute of Fermentation, Osaka | |
| Institute of Immunology Co., Ltd | |
| Institute of Information Security | |
| Institute of Management & Research, Jalgaon | |
| Institute of Science Tokyo | |
| Institute of Science Tokyo - School of Computing | Tokyo |
| Institute of Space and Astronautical Science | |
| Institute of Statistical Mathematics | Tokyo |
| Institute of Systems, Information Technologies and Nanotechnologies | |
| Institute of Technologists | |
| inSure, Inc. | |
| int21 Corporation | Tokyo |
| Intec, Inc. | Tokyo |
| Integra, Inc. | Tokyo |
| Integral Technology Co., Ltd | Osaka |
| IntegriCulture, Inc. | |
| Intelligent Wave, Inc. | Tokyo |
| IntelliJapan Co., Ltd | Tokyo |
| Inter Mesh Japan Co., Ltd | Tokyo |
| Inter-src, Inc. | Tokyo |
| Inter-Tel Japan, Inc. | Tokyo |
| Inter-University Research Institute Corporation High Energy Accelerator Research Organisation | |
| Inter-University Research Institute Corporation Research Organization of Information and Systems | Tokyo |
| Interactive Solutions Co., Ltd | Tokyo |
| Interactot Ltd | |
| Interarrows, Inc. | Tokyo |
| Intercom, Inc. | Tokyo |
| Interfactory Partners Co., Ltd | |
| InterJapan | Saitama |
| Interlink | Tokyo |
| International Advanced Technology Corporation | Tokyo |
| International Budo University | |
| International Christian University | |
| International College of Liberal Arts | |
| International College of Technology, Kanazawa | |
| International Information Science Foundation | Tokyo |
| International Laboratory Corporation | |