| Name | In-House Group | Constituency/Area |
|---|---|---|
| MABUCHI Sumio | CDP | Nara 1st District |
| MADOKA Yoriko | DPFP | Tokyo Bloc |
| MAEHARA Seiji | JIP | Kyoto 2nd District |
| MAKI Yoshio | CDP | Aichi 4th District |
| MAKISHIMA Karen | LDP | Kanagawa 17th District |
| MANO Satoshi | CDP | Tokai Bloc |
| MARUO Keisuke | CDP | Kyushu Bloc |
| MASUTA Sekio | CDP | Tohoku Bloc |
| MATSUBARA Jin | Ind | Tokyo 26th District |
| MATSUDA Isao | CDP | Tokai Bloc |
| MATSUKI Kenko | CDP | Hokkaido 2nd District |
| MATSUMOTO Hisashi | LDP | Chiba 13th District |
| MATSUMOTO Takeaki | LDP | Hyogo 11th District |
| MATSUMOTO Yohei | LDP | Tokyo Bloc |
| MATSUNO Hirokazu | LDP | Chiba 3rd District |
| MATSUO Akihiro | CDP | Tokyo 7th District |
| MATSUSHIMA Midori | LDP | Tokyo 14th District |
| MATSUSHITA Reiko | CDP | Tokyo Bloc |
| MICHISHITA Daiki | CDP | Hokkaido 1st District |
| MIDORIKAWA Takashi | CDP | Akita 2nd District |
| MIKI Kee | JIP | Kinki Bloc |
| MINOBE Teruo | JIP | Osaka 4th District |
| MINORIKAWA Nobuhide | LDP | Tohoku Bloc |
| MISUMI Sota | CDP | Kita Kanto Bloc |
| MITANI Hidehiro | LDP | Minami Kanto Bloc |
| MITAZONO Satoshi | LDP | Kagoshima 2nd District |
| MIYAJI Takuma | LDP | Kyushu Bloc |
| MIYAKAWA Shin | CDP | Minami Kanto Bloc |
| MIYASHITA Ichiro | LDP | Nagano 5th District |
| MIYAUCHI Hideki | LDP | Fukuoka 4th District |
| MIYAZAKI Masahisa | LDP | Kyushu Bloc |
| MIZUNUMA Hideyuki | CDP | Chiba 4th District |
| MORI Eisuke | LDP | Chiba 11th District |
| MORI Yosuke | DPFP | Tokyo Bloc |
| MORISHIMA Tadashi | YK | Osaka 2nd District |
| MORISHITA Chisato | LDP | Tohoku Bloc |
| MORITA Toshikazu | CDP | Saitama 12th District |
| MORIYAMA Hiroshi | LDP | Kagoshima 4th District |
| MORIYAMA Hiroyuki | CDP | Kinki Bloc |
| MOTEGI Toshimitsu | LDP | Tochigi 5th District |
| MOTOMURA Nobuko | JCP | Tokai Bloc |
| MUKOYAMA Jun | LDP | Hokkaido Bloc |
| MUKOYAMA Koichi | DPFP | Kinki Bloc |
| MURAI Hideki | LDP | Saitama 1st District |
| MURAKAMI Seiichiro | LDP | Shikoku Bloc |
| MURAKAMI Tomonobu | JIP | Fukuoka 11th District |
| MURAOKA Toshihide | DPFP | Akita 3rd District |
| MUTO Yoji | LDP | Gifu 3rd District |
Notes:
* No abbreviation
List of the In-House Groups in the House
District: Single-seat constituency
Bloc: Proportional representation area
In-House Group: A group of House Members who engage in joint activities within the House. Usually, a political party forms an in-House group inside the House, but occasionally there are cases where a group is formed by (1) House Members who do not belong to a particular political party, (2) a political party and a House Member or Members who do not belong to any political party, or (3) two or more political parties.