List of districts of the House of Representatives of Japan

As of 2005^[update], 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 (multi-member) 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 (250 each) and the possibility of split voting. But the bill was stalled in the House of Councillors. After the Liberal Democratic Party (LDP) 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.

The Block constituency for Hokkaidō (比例北海道ブロック) elects 8 members proportionally. It comprises Hokkaidō Prefecture, which is divided into 12 single-member districts.

...
Wikipedia