| Agood Co., Ltd | Shizuoka |
| Agora-Soft Co., Ltd | Tokyo |
| Agrist Co., Ltd | Miyazaki |
| AGS Corporation | Saitama |
| AH-Software | Tokyo |
| Ahead Biocomputing Co., Ltd | Kanagawa |
| AI Inside Co., Ltd | Tokyo |
| AI Medical Service Co., Ltd | Tokyo |
| Ai Robotics Co., Ltd | Tokyo |
| AI Samurai, Inc. | |
| AI-Lab | Tokyo |
| ai-Link | Tokyo |
| Aichi Bank Ltd | |
| Aichi Bunkyo Women's College | |
| Aichi Gakuen University | |
| Aichi Gakusen University / College | |
| Aichi Institute of Technology | Tokyo |
| Aichi Medical University | |
| Aichi Mizuho University | |
| Aichi Prefectural University - School of Information Science and Technology | |
| Aichi University of Education | |
| Aichi University of Technology | |
| Aii Electronic Co., Ltd | Nagano |
| Aikis | Tokyo |
| Aikoku Gakuen Junior College | |
| Aikoku Gakuen University | |
| Aim at Entertainment, Inc. | Tokyo |
| AIM internet-service Co., Ltd | Tokyo |
| Aimsnet, Inc. | Tokyo |
| Aino University | |
| Aiphone Co., Ltd | Aichi |
| aiQ Corp. Ltd | Tokyo |
| Air Internet Service Co., Ltd | Tokyo |
| Air Internet Service Co., Ltd | Tokyo |
| AIS Co., Ltd | Tokyo |
| Aishin Co., Ltd | Tokyo |
| Aisin System Co., Ltd | Ehime |
| Aisys Co., Ltd | Tokyo |
| Aisys, Inc. | |
| Aitai net | Tokyo |
| AIVY Communications | Tokyo |
| Akibakan | Tokyo |
| Akita University | |
| Akita University - Department of Computer Science and Engineering | Akita |
| Akita University - Department of Electrical and Electronic Engineering | Akita |
| Akita University of Nursing and Welfare | |
| aLab Co., Ltd | Tokyo |
| Alche, Inc. | |
| ALE Co., Ltd | |
| ALE-NET | Tokyo |