| Hyogo University | |
| Hyper Lab | Tokyo |
| HYS Co., Ltd | Tokyo |
| i Magazine | |
| i Magazine Co., Ltd | Tokyo |
| i Nations Co., Ltd | Tokyo |
| I Net Lily Corporation | Tokyo |
| i-Learning Co., Ltd | Tokyo |
| i-Live | Tokyo |
| I-NET Co., Ltd | Miyazaki |
| I-Net Corporation | Tokyo |
| I-O Data Device Co., Ltd | Ishikawa |
| I-O Data Device, Inc. | Ishikawa |
| i-Rabbit Co., Ltd | Tokyo |
| I.A.I. Co., Ltd | Tokyo |
| i3 Digital Corporation | |
| iA, Inc. | Tokyo |
| IAI Corporation | Shizuoka |
| IAJ Co., Ltd | Hyogo |
| iBank Marketing Co., Ltd | Tokyo |
| Ibaraki Christian University | |
| Ibaraki Prefectural University of Health Sciences | |
| Ibaraki University | |
| IBC Corporation | Tokyo |
| IBIS Co., Ltd | Osaka |
| IBM Research - Tokyo | Tokyo |
| Ibnet, Inc. | Aichi |
| iBODY Japan Co., Ltd | Tokyo |
| IC-Net | Tokyo |
| IC-NET Co., Ltd | Tokyo |
| iCall Co., Ltd | Tokyo |
| Icom, Inc. | |
| icomt Corporation | Miyazaki |
| ICSOFT Co., Ltd | Aichi |
| ICZOO Corporation | Tokyo |
| ID Networks Co., Ltd | Tokyo |
| IDC Frontier, Inc. | |
| IDEAAI Co., Ltd | Tokyo |
| IDEACLIP, Inc. | Tokyo |
| Ideal Co., Ltd | Fukuoka |
| Idenbrid, Inc. | |
| IDNIS Ltd | |
| IDOM CaaS Technology Co., Ltd | Tokyo |
| Idrasys Co., Ltd | Tokyo |
| IDS Co., Ltd | Iwate |
| IFTOR | Tokyo |
| iHeart Japan Corporation | Kyoto |
| IHI Aerospace Co., Ltd. | |
| Ikegami Tsushinki Co., Ltd | Tokyo |
| Ikenobo Junior College | |