List of districts of the House of Representatives of Japan


, the House of Representatives of Japan is elected from a combination of multi-member districts and single-member districts. Currently, 180 members are elected from 11 multi-member districts by a party-list system of proportional representation, and 295 members are elected from single-member districts, for a total of 475. 238 seats are therefore required for a majority.
Each Block district spans one or more Prefectures, and each Prefecture spans one or more single-member district, so the districts are organized by Block district and then by Prefecture. In general, the Block districts correspond loosely to the major Regions of Japan, with some of the larger regions subdivided.
Up to the 1993 general election all members of the House of Representatives were elected in multi-member constituencies by single non-transferable vote. In 1994, parliament passed an electoral reform bill that introduced the current system of parallel voting in single-member constituencies and proportional voting blocks. The original draft bill in 1993 by the anti-LDP coalition of Prime Minister Morihiro Hosokawa included proportional party list voting on a national scale, an equal number of proportional and district seats and the possibility of split voting. But the bill was stalled in the House of Councillors. After the Liberal Democratic Party had returned to power later that year, it was changed to include proportional voting in regional blocks only, the number of proportional seats was reduced, but the possibility to cast two separate votes was kept in the bill. The electoral reform law was finally passed in 1994. It was first applied in the 1996 general election.

[Hokkaidō]

The Block constituency for Hokkaidō elects 8 members proportionally. It comprises Hokkaidō Prefecture, which is divided into 12 single-member districts.

[Hokkaidō Prefecture]

[Tohoku]

The Block constituency for Tohoku elects 14 members proportionally.

[Akita Prefecture]

[Aomori Prefecture]

[Fukushima Prefecture]

[Iwate Prefecture]

[Miyagi Prefecture]

[Yamagata Prefecture]

[Kitakanto]

The Block constituency for Kitakanto elects 20 members proportionally. It includes the northern part of the Kantō region.

[Gunma Prefecture]

[Ibaraki Prefecture]

[Saitama Prefecture]

[Tochigi Prefecture]

[Minamikanto]

The Block constituency for southern Kanto elects 22 members proportionally. It includes the southern part of the Kantō region.

[Chiba Prefecture]

[Kanagawa Prefecture]

[Yamanashi Prefecture]

Tokyo

The Block constituency for Tokyo elects 17 members proportionally.

[Tokyo Metropolis]

[Hokurikushinetsu]

The Block constituency for Hokurikushinetsu elects 11 members proportionally. It corresponds to the Hokuriku region and the Shin'etsu region.

[Fukui Prefecture]

[Ishikawa Prefecture]

[Niigata Prefecture]

[Nagano Prefecture]

[Toyama Prefecture]

Tokai">Tōkai region">Tokai

The Block constituency for Tokai elects 21 members proportionally.

[Aichi Prefecture]

[Gifu Prefecture]

[Mie Prefecture]

[Shizuoka Prefecture]

[Kinki]

The Block constituency for Kinki elects 29 members proportionally.

[Hyōgo Prefecture]

[Kyoto Prefecture]

[Nara Prefecture]

[Osaka Prefecture]

[Shiga Prefecture]

[Wakayama Prefecture]

[Chugoku]

The Block constituency for Chugoku elects 11 members proportionally.

[Hiroshima Prefecture]

[Okayama Prefecture]

[Shimane Prefecture]

[Tottori Prefecture]

[Yamaguchi Prefecture]

[Shikoku]

The Block constituency for Shikoku elects 6 members proportionally.

[Ehime Prefecture]

[Kagawa Prefecture]

[Kōchi Prefecture]

[Tokushima Prefecture]

[Kyūshū]

The Block constituency for Kyūshū elects 21 members proportionally. It includes Okinawa Prefecture as well.

[Fukuoka Prefecture]

[Kagoshima Prefecture]

[Kumamoto Prefecture]

[Miyazaki Prefecture]

[Nagasaki Prefecture]

[Ōita Prefecture]

[Okinawa Prefecture]

[Saga Prefecture]

Redistricting and reapportionment

Amendments to the electoral law in 2002 and 2013 changed the boundaries of single-member districts and reapportioned seats between prefectures. The borders of the regional proportional blocks have never changed, but the apportionment of seats to the regional proportional blocks changed in 2000 after the number of proportional seats had been reduced from 200 to 180, and in the 2002 reapportionment.
Another reapportionment was passed by the National Diet in June 2017. In the majoritarian segment, it will change 97 districts in 19 prefectures, six are eliminated without replacement. In the proportional segment, four "blocks" lose a seat each. Thus, the number of majoritarian seats is reduced to 289, the number of proportional seats to 176, the House of Representatives overall shrinks to 465. The reform takes effect one month after promulgation, i.e. on July 16, 2017.