| MG Co., Ltd | |
| MICARD Co., Ltd | Tokyo |
| MicNet | Tokyo |
| Micro Summit K.K | |
| Micro Technica Co., Ltd | Tokyo |
| Micron, Inc. | |
| Micronet Co., Ltd | |
| Micronics Japan Co., Ltd | Tokyo |
| Microsoft Japan | Tokyo |
| MIcrotech Laboratory, Inc. | |
| Micware Co., Ltd | Hyogo |
| Midokura | Tokyo |
| Mie Prefectural College of Nursing | |
| Mie University | |
| Mikasa Shoji Co., Ltd | |
| Mileruntech Co., Ltd | Tokyo |
| Milize Investment Co., Ltd | Tokyo |
| Mimasaka University | |
| Mimido Co., Ltd | Tokyo |
| Minami Kyushu University | |
| Minami Kyushu University Junior College | |
| Minatogawa College | |
| Minc Internet Co., Ltd | Tokyo |
| Minkabu The Infonoid Co., Ltd | Tokyo |
| Minosys Co., Ltd | Tokyo |
| Mint | |
| Minto, Inc. | |
| MiraBiologics Co., Ltd | Tokyo |
| Mirai Communication Network, Inc. | Tokyo |
| Mirai Lab Co., Ltd | Miyazaki |
| Mirise Technologies Co., Ltd | Aichi |
| MIS | Tokyo |
| MIS Co., Ltd | |
| Mishima Gakuen Educational Institution Comprises | |
| MiSPO Co., Ltd | Kanagawa |
| Misumi Group, Inc. | |
| MIT Co., Ltd | Tokyo |
| MIT System Research Institute Co., Ltd | Tokyo |
| Mitsubishi Chemical Group Corporation | |
| Mitsubishi Electric Corporation | Tokyo |
| Mitsubishi Electric Corporation | |
| Mitsubishi HC Capital Co., Ltd | Tokyo |
| Mitsubishi Heavy Industries Ltd | |
| Mitsubishi Materials Corporation | Tokyo |
| Mitsubishi Research Institute, Inc. | Tokyo |
| Mitsubishi UFJ Capital Co., Ltd | Tokyo |
| Mitsubishi UFJ Financial Group, Inc. | |
| Mitsue-Links Co., Ltd | Tokyo |
| Mitsui & Co., Ltd | |
| Mitsui Bussan Secure Directions, Inc. | |