| Photo | Name | In-House Group | Constituency/Area |
|---|---|---|---|
 | Mr. YAGAMI Masayoshi | CDP | Kyushu Bloc |
 | Mr. YAGI Tetsuya | LDP | Tokai Bloc |
 | Mr. YAMADA Kenji | LDP | Hyogo 7th District |
 | Ms. YAMADA Miki | LDP | Tokyo Bloc |
 | Mr. YAMAGIWA Daishiro | LDP | Kanagawa 18th District |
 | Mr. YAMAGUCHI Shunichi | LDP | Tokushima 2nd District |
 | Mr. YAMAGUCHI Taimei | LDP | Saitama 10th District |
 | Mr. YAMAGUCHI Tsuyoshi | LDP | Hyogo 12th District |
 | Mr. YAMAHANA Ikuo | CDP | Tokyo Bloc |
 | Ms. YAMAKAWA Yuriko | CDP | Kita Kanto Bloc |
 | Mr. YAMAMOTO Koichi | LDP | Ehime 4th District |
 | Mr. YAMAMOTO Kozo | LDP | Fukuoka 10th District |
 | Mr. YAMAMOTO Taku | LDP | Hokuriku-Shinetsu Bloc |
 | Mr. YAMAMOTO Tomohiro | LDP | Minami Kanto Bloc |
 | Ms. YAMAMOTO Wakako | CDP | Hokuriku-Shinetsu Bloc |
 | Mr. YAMAMOTO Yuji | LDP | Shikoku Bloc |
 | Mr. YAMANOI Kazunori | * | Kinki Bloc |
 | Ms. YAMAO Shiori | CDP | Aichi 7th District |
 | Mr. YAMAOKA Tatsumaru | * | Hokkaido Bloc |
 | Mr. YAMASHITA Takashi | LDP | Okayama 2nd District |
 | Mr. YAMAUCHI Koichi | CDP | Kyushu Bloc |
 | Mr. YAMAZAKI Makoto | CDP | Tohoku Bloc |
 | Mr. YANA Kazuo | LDP | Tochigi 3rd District |
 | Mr. YOKOMITSU Katsuhiko | CDP | Kyushu Bloc |
 | Mr. YOSHIDA Tsunehiko | CDP | Tokai Bloc |
 | Mr. YOSHIIE Hiroyuki | LDP | Kanagawa 16th District |
 | Mr. YOSHIKAWA Hajime | SDP | Kyushu Bloc |
 | Mr. YOSHIKAWA Takamori | LDP | Hokkaido 2nd District |
 | Mr. YOSHINO Masayoshi | LDP | Fukushima 5th District |
 | Mr. YUNOKI Michiyoshi | * | Chugoku Bloc |
Notes:
* No abbreviation
List of the In-House Groups in the House
In principle, House Members' names are spelled with the Hepburn system.
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.
