| AlfaCom Ltd | Tokyo |
| Alfactory Co., Ltd | |
| Alfresa Holdings Corporation | Tokyo |
| Algae Science Japan Co., Ltd | Okinawa |
| Alinco, Inc. | Osaka |
| Alive Co., Ltd | Tokyo |
| All Right Co., Ltd | Kanagawa |
| Alles Net | Tokyo |
| Allied Telesis | Tokyo |
| Allm, Inc. | |
| Allsmart Co., Ltd | Tokyo |
| Almex Technologies, Inc. | |
| Alpha Co., Ltd | Tokyo |
| Alpha Code Co., Ltd | Tokyo |
| Alpha Electronics Corporation | Tokyo |
| Alpha Link Co., Ltd | Tokyo |
| Alpha Net Co., Ltd | Tokyo |
| Alpha Systems, Inc. | Tokyo |
| Alphasting Co., Ltd | Osaka |
| Alphasystem Corporation | Yamagata |
| Alphaus, Inc. | |
| Alpine Electronics, Inc. | Tokyo |
| Alps Alpine Co., Ltd | Tokyo |
| Alps Alpine Co., Ltd | |
| Alt Co., Ltd | Tokyo |
| ALT Co., Ltd | Tokyo |
| AM Japan Co., Ltd | Tokyo |
| Amateras | Tokyo |
| Amaya Co., Ltd | Saitama |
| AMG Solution Co., Ltd | Tokyo |
| AMIC Co., Ltd | Nara |
| Amirobo Tech, Inc. | |
| Amptalk Co., Ltd | Tokyo |
| Amufi, Inc. | |
| ANA Digital Gate Co., Ltd | Tokyo |
| Anaheim Technology | Tokyo |
| Andor Co., Ltd | Tokyo |
| ANDPAD | |
| Andpad Co., Ltd | Miyagi |
| Angel Bridge Co., Ltd | Tokyo |
| Anges Co., Ltd | Osaka |
| ANK Company Co., Ltd | Tokyo |
| Annie Co., Ltd | Tokyo |
| Annis Corporation | Tokyo |
| ANOBAKA Co., Ltd | Tokyo |
| Anokaba Human Capital | Tokyo |
| Another Lane Co., Ltd | Tokyo |
| ANRI | Tokyo |
| Anritsu | Kanagawa |
| Antaa Co., Ltd | Tokyo |