# Ōita at-large district

Ōita at-large district is a constituency in the House of Councillors of Japan, the upper house of the Diet of Japan (national legislature). It currently elects 2 members to the House of Councillors, 1 per election. It is unique among other Kyushu conservative kingdoms for its willingness to elect opposition members. Shinya Adachi held the districts first seat from 2004, and Kiyoshi Adachi held the second seat until his resignation in 2023, with Tadatomo Yoshida losing the by-election after by an extremely slim margin. This is possibly due to the presence of the city of Ōita, which has shown a willingness to support opposition candidates; it was historically also represented by a second Japan Socialist Party Councilor.

## Elected members of House of Councillors

| Class of (1947/1953/...) | Election | Class of (1950/1956/...) |
| #1 1947: #1, 6 Year Term | Election | #1 1947: #2, 3 Year Term |
| Jinzo Iwao (NCP) | 1947 | Masaji Hitotsumatsu (LP) |
| Jinzo Iwao (NCP) | 1950 | Masaji Hitotsumatsu (Yoshida LP) |
| Fumio Gotō (Indep.) | 1953 | Masaji Hitotsumatsu (Yoshida LP) |
| Fumio Gotō (Indep.) | 1956 | Yoshitaka Goto (LDP) |
| Haruzo Murakami (LDP) | 1959 | Yoshitaka Goto (LDP) |
| Haruzo Murakami (LDP) | 1962 | Yoshitaka Goto (LDP) |
| Haruzo Murakami (LDP) | 1965 | Yoshitaka Goto (LDP) |
| Haruzo Murakami (LDP) | 1968 | Yoshitaka Goto (LDP) |
| Ryohei Kudo (JSP) | 1971 | Yoshitaka Goto (LDP) |
| Ryohei Kudo (JSP) | 1974 | Hidekazu Iwao † 1976 (LDP) |
| Ryohei Kudo (JSP) | 1976 by-election | Masao Goto (OFF) |
| Seishirō Etō (ATSNS) | 1977 | Masao Goto (OFF) |
| Seishirō Etō (ATSNS) | 1980 | Masao Goto (LDP) |
| Keigi Kajiwara (JSP) | 1983 | Masao Goto (LDP) |
| Keigi Kajiwara (JSP) | 1986 | Masao Goto (LDP) |
| Keigi Kajiwara (JSP) | 1989 | Masao Goto (LDP) |
| Keigi Kajiwara (JSP) | 1992 | Ban Kugimiya (LDP) |
| Keigi Kajiwara (JSP) | 1995 | Ban Kugimiya (LDP) |
| Keigi Kajiwara (JSP) | 1998 | Toshiya Nakamichi (LDP) |
| Hiroko Goto (LDP) | 2001 | Toshiya Nakamichi (LDP) |
| Hiroko Goto (LDP) | 2004 | Shinya Adachi (DPJ) |
| Yōsuke Isozaki (LDP) | 2007 | Shinya Adachi (DPJ) |
| Yōsuke Isozaki (LDP) | 2010 | Shinya Adachi (DPJ) |
| Yōsuke Isozaki (LDP) | 2013 | Shinya Adachi (DPJ) |
| Yōsuke Isozaki (LDP) | 2016 | Shinya Adachi (DP) |
| Kiyoshi Adachi (Indep.) | 2019 | Shinya Adachi (DP) |
| Kiyoshi Adachi (Indep.) | 2022 | Harutomo Kosho (LDP) |
| Aki Shirasaka (LDP) | 2023 by-election | Harutomo Kosho (LDP) |
OFF - Oita Farrmers Federation ASTNS - Association To Send a New Style to National Politics †: Died in Office

## Election results

2023 by-election :
| Party | Party | Candidate | Votes | % | ±% |
| | LDP | Aki Shirasaka [ja] | 196,122 | 50.04 | 3.46 |
| | CDP | Tadatomo Yoshida | 195,781 | 49.96 | New |
| Registered electors | Registered electors | Registered electors | 943,477 | | |
| Turnout | Turnout | Turnout | | 42.48 | 10.50 |
2022 :
| Party | Party | Candidate | Votes | % | ±% |
| | LDP | Harutomo Kosho [ja] | 228,417 | 46.58 | 0.52 |
| | DPP | Shinya Adachi (Incumbent) | 183,258 | 37.37 | New |
| | JCP | Kai Yamashita | 35,705 | 7.28 | 3.73 |
| | Sanseitō | Yūko Shigematsu | 21,723 | 4.43 | New |
| | Anti-NHK | Taizo Ninomiya | 10,770 | 2.20 | 2.19 |
| | Independent | Yūichi Kotegawa | 10,512 | 2.14 | New |
| Registered electors | Registered electors | Registered electors | 950,511 | | |
| Turnout | Turnout | Turnout | | 52.98 | 2.44 |
2019 :
| Party | Party | Candidate | Votes | % | ±% |
| | Independent | Kiyoshi Adachi | 236,153 | 49.55 | New |
| | LDP | Yōsuke Isozaki (Incumbent) | 219,498 | 46.06 | 1.88 |
| | Anti-NHK | Taizo Ninomiya | 20,909 | 4.39 | New |
| Registered electors | Registered electors | Registered electors | 969,453 | | |
| Turnout | Turnout | Turnout | | 50.54 | 7.84 |
2016 :
| Party | Party | Candidate | Votes | % | ±% |
| | DP | Shinya Adachi (Incumbent) | 271,783 | 48.13 | New |
| | LDP | Harutomo Kosho | 270,693 | 47.94 | 2.04 |
| | HRP | Atsuko Ueda | 22,153 | 3.92 | 1.08 |
| Registered electors | Registered electors | Registered electors | 989,634 | | |
| Turnout | Turnout | Turnout | | 58.38 | 5.23 |
2013 :
| Party | Party | Candidate | Votes | % | ±% |
| | LDP | Yōsuke Isozaki (Incumbent) | 250,915 | 49.98 | 7.41 |
| | Independent | Shintaro Goto | 137,049 | 27.30 | New |
| | JCP | Kai Yamashita | 55,249 | 11.01 | 2.26 |
| | YP | Hideki Urano | 44,542 | 8.87 | New |
| | HRP | Atsuko Ueda | 14,265 | 2.84 | New |
| Registered electors | Registered electors | Registered electors | 981,222 | | |
| Turnout | Turnout | Turnout | | 53.15 | 9.81 |
2010 :
| Party | Party | Candidate | Votes | % | ±% |
| | DPJ | Shinya Adachi (Incumbent) | 294,286 | 48.68 | 6.14 |
| | LDP | Kiyoshi Odawara [ja] | 257,322 | 42.57 | 9.93 |
| | JCP | Kai Yamashita | 52,863 | 8.75 | 2.57 |
| Registered electors | Registered electors | Registered electors | 990,648 | | |
| Turnout | Turnout | Turnout | | 62.96 | 5.23 |