Japanese Elections - National Elections

National Elections

The National Diet (Kokkai) has two chambers. The House of Representatives (Shugi-in) has 480 members, elected for a four-year term, 300 members in single-seat constituencies and 180 members by proportional representation in 11 block districts. In this system, each voter votes twice, once for a candidate in the local constituency, and once for a party, each of which has a list of candidates for each block district. The local constituencies are decided by plurality, and the block seats are then handed out to party lists proportionally (by the D'Hondt method) to their share of the vote. Often the parties assign the block list spots to single-seat candidates, so that unsuccessful single-seat candidates have a chance to be elected in the proportional block. Parties may also place dual district and block candidates on the same list rank; in that case, the Sekihairitsu system determines the order of candidates. General elections of members of the House of Representatives (Shūgiin giin sō-senkyo) are usually held before the end of a four-year term as the chamber may be dissolved by the cabinet (via the Emperor). Most prime ministers use that option. The only exception in post-war history was the "Lockheed election" of 1976 in which the Liberal Democratic Party lost its seat majority for the first time.

The House of Councillors (Sangi-in) has 242 members, elected for a six-year term, 146 members in 47 single- and multi-seat constituencies (prefectures) by single non-transferable vote and 96 by proportional representation (by D'Hondt method) on the national level. The proportional election to the House of Councillors allows the voters to cast a preference vote for a single candidate on a party list. The preference votes exclusively determine the ranking of candidates on party lists. Half of the House of Councillors comes up for election every three years in regular elections of members of the House of Councillors (Sangiin giin tsūjō-senkyo).

Vacant district seats in both Houses are generally filled in by-elections (hoketsu senkyo). Nowadays, these are usually scheduled in April and October as necessary. Vacant proportional seats in both Houses and district seats in the House of Councillors that fall vacant within three months of a regular election are filled by kuriage-tōsen (roughly "being elected as runner-up"): the highest ranking candidate on a proportional list or in the electoral district who was not elected and is not disqualified takes the seat. Disqualifications may, for example, happen if a candidate for the House of Councillors runs for the House of Representatives or vice versa, or after a violation of campaign laws.

For many years Japan was a one party dominant state until 1993 with the Liberal Democratic Party as the ruling party. It won a majority of the popular vote in House of Representatives general elections until the 1960s. It lost the majority of seats in 1976 and 1979, but continued to rule without coalition partners with the support of independent Representatives. After the 1983 election when it again lost the majority, it entered a coalition for the first time – with the New Liberal Club. In 1986, the coalition ended as the LDP won a large majority of seats and even came close to a majority of votes. The party suffered its first clear electoral defeat in the 1989 House of Councillors regular election when it lost the upper house majority and had to face for the first time a divided Diet (nejire Kokkai, lit. "twisted Diet") where passing legislation depends on cooperation with the opposition. The LDP was out of government for the first time in 1993 after Ichirō Ozawa and his faction had left the party and the opposition parties united in an anti-LDP coalition, but then soon returned to the majority in 1994 by entering a coalition with its traditional main opponent, the Socialist Party. The 2009 House of Representatives elections handed the first non-LDP victory to the Democratic Party of Japan. Due to the majoritarian parallel voting system it is unlikely that Japan will develop a multi-party system, but there is speculation that after 2009, Japan will develop a two-party system.

According to a survey by Yomiuri Shimbun in April 2010, almost half of Japanese voters do not support any political parties due to political inefficiency.