| Name | In-House Group | Constituency/Area |
|---|---|---|
| MAEHARA Seiji | JIP | Kyoto 2nd District |
| MAEKAWA Megumi | LDP | Kita Kanto Bloc |
| MAKINO Shunichi | SAN | Kyushu Bloc |
| MAKISHIMA Karen | LDP | Kanagawa 17th District |
| MARUKAWA Tamayo | LDP | Tokyo 7th District |
| MARUO Natsuko | LDP | Kanagawa 1st District |
| MARUTA Koichiro | LDP | Kanagawa 13th District |
| MATSUMOTO Hisashi | LDP | Chiba 13th District |
| MATSUMOTO Izumi | LDP | Chiba 8th District |
| MATSUMOTO Yohei | LDP | Tokyo 19th District |
| MATSUNO Hirokazu | LDP | Chiba 3rd District |
| MATSUSHIMA Midori | LDP | Tokyo 14th District |
| MATSUSHITA Hideki | LDP | Hokkaido 9th District |
| MIHARA Asato | LDP | Kyushu Bloc |
| MIKI Kee | JIP | Kinki Bloc |
| MINESHIMA Yuya | MIRAI | Tokyo Bloc |
| MINOBE Teruo | JIP | Osaka 4th District |
| MINORIKAWA Nobuhide | LDP | Tohoku Bloc |
| MITANI Hidehiro | LDP | Kanagawa 8th District |
| MITAZONO Satoshi | LDP | Kagoshima 2nd District |
| MITSUBAYASHI Hiromi | LDP | Saitama 13th District |
| MIYAJI Takuma | LDP | Kagoshima 1st District |
| MIYASHITA Ichiro | LDP | Nagano 5th District |
| MIYAUCHI Hideki | LDP | Fukuoka 4th District |
| MIYAZAKI Masahisa | LDP | Okinawa 2nd District |
| MIZUNO Yoshihiko | LDP | Aichi 3rd District |
| MORI Eisuke | Ind | Chiba 11th District |
| MORI Yosuke | DPFP | Tokyo Bloc |
| MORIHARA Kiyoko | LDP | Tokyo Bloc |
| MORISHITA Chisato | LDP | Miyagi 4th District |
| MORIYAMA Hiroshi | LDP | Kagoshima 4th District |
| MORIYAMA Masahito | LDP | Hyogo 1st District |
| MOTEGI Toshimitsu | LDP | Tochigi 5th District |
| MUKOYAMA Jun | LDP | Hokkaido 8th District |
| MUKOYAMA Koichi | DPFP | Kinki Bloc |
| MUNEKIYO Koichi | LDP | Kinki Bloc |
| MURAI Hideki | LDP | Saitama 1st District |
| MURAKAMI Seiichiro | LDP | Shikoku Bloc |
| MURAKAMI Tomonobu | JIP | Kyushu Bloc |
| MURAKI Nagisa | LDP | Hokkaido Bloc |
| MURAOKA Toshihide | DPFP | Akita 3rd District |
| MUTO Kazuko | MIRAI | Kita Kanto Bloc |
| MUTO Yoji | LDP | Gifu 3rd District |
Notes:
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.