Elections in Japan

Japan's postwar national legislature, the National Diet (国会, Kokkai), has two directly elected chambers, elected on independent electoral cycles:

• The House of Representatives (衆議院, Shūgi-in) has 465 members, elected for a rarely completed four-year term, 289 members in single-seat constituencies and 176 members by proportional representation in 11 regional "block" constituencies.

General elections of members of the House of Representatives (衆議院議員総選挙, Shūgi-in 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 single-seat constituencies are decided by plurality, and the proportional seats are handed out in each "block" constituency to party lists proportionally (by the D'Hondt method) to their share of the vote. Each voter votes twice, once for a candidate in the local constituency, and once for a party in the regional "block" constituency. In a parallel system, there is no link between votes in one tier and seat numbers in the other; but so-called dual candidacies (重複立候補, jūfuku rikkōho) of one candidate in both tiers simultaneously are allowed. If such dual candidates lose in the majoritarian tier, they still 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 (惜敗率, ratio of margin of defeat) system determines the order of candidates.

• The House of Councillors (参議院, Sangi-in) has 245 members (248 from 2022),[2] elected for a fixed six-year term, 147 (2022–: 148) members by single non-transferable vote (SNTV) in 45 single- and multi-seat constituencies (most are prefectures, two combined constituencies comprise two neighbouring prefectures each) and 98 (2022–: 100) by proportional representation (by D'Hondt method) with optionally open lists in a single, nationwide constituency.

In staggered elections, half of the House of Councillors comes up for election every three years in regular/ordinary elections of members of the House of Councillors (参議院議員通常選挙, Sangi-in giin tsūjō-senkyo). The term is fixed, the House of Councillors cannot be dissolved. This, too, is a parallel electoral system. Dual candidacies are not allowed. As in House of Representatives elections, voters have two votes: In the majoritarian election, the vote has to be for a candidate, but in the proportional election, the vote may be for either a party list or a single candidate; in the latter case, the vote counts as both a vote for the party list (to determine proportional seat distribution), and as a preference vote within that list (to determine the order or proportional candidates within that list). The district magnitudes in the majoritarian tier vary between one and six, dependent on, but not fully proportional to the population of each prefecture. In single-member constituencies, SNTV becomes equivalent to first-past-the-post, whereas seats are usually split between different parties/alliances in multi-member constituencies (and in the proportional constituency by definition). Therefore, the single-member constituencies of the House of Councillors (参議院一人区, Sangiin ichinin-ku) are more likely to swing the election result and often receive more media and campaign attention. 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 strictly determined the ranking of candidates on party lists before 2019. Since the 2019 election, parties are allowed to prioritize individual candidates on their proportional list over voter preferences in a "special frame" (特定枠, tokutei-waku). In the 2019 election, almost all parties continued to use completely open lists; exceptions were the LDP which used the "special frame" to give secure list spots to two LDP prefectural federations affected by the introduction of combined constituencies in 2016, Reiwa Shinsengumi which used it to give secure list spots to two candidates with severe disabilities, and the minor "Labourers' Party for the liberation of labour".[3][4]

Voting in Higashiōsaka, Osaka Prefecture, Japan, 2014.

The electoral cycles of the two chambers of the Diet are usually not synchronized. Even when the current constitution took effect in 1947, the first House of Councillors election was held several days apart from the 23rd House of Representatives election. Only in 1980 and 1986, general and regular election coincided on the same day because the House of Representatives was dissolved in time for the election to be scheduled together with the House of Councillors election in early summer.

Vacant district seats in both Houses are generally filled in by-elections (補欠選挙, 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 (繰り上げ当選, 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 (自由民主党, Jiyū-Minshu-tō) 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 (新自由クラブ, Shin-Jiyū-kurabu). 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 (ねじれ国会, 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 Japan Socialist Party (日本社会党, Nihon-Shakai-tō). The 2009 House of Representatives elections handed the first non-LDP victory to the Democratic Party of Japan (民主党, Minshu-tō).

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.[5]

In the 1980s, apportionment of electoral districts still reflected the distribution of the population in the years following World War II, when only one-third of the people lived in urban areas and two thirds lived in rural areas. In the next forty-five years, the population became more than three-quarters urban, as people deserted rural communities to seek economic opportunities in Tokyo and other large cities. The lack of reapportionment led to a serious underrepresentation of urban voters. Urban districts in the House of Representatives were increased by five in 1964, bringing nineteen new representatives to the lower house; in 1975 six more urban districts were established, with a total of twenty new representatives allocated to them and to other urban districts. Yet great inequities remained between urban and rural voters.

In the early 1980s, as many as five times the votes were needed to elect a representative from an urban district compared with those needed for a rural district. Similar disparities existed in the prefectural constituencies of the House of Councillors. The Supreme Court had ruled on several occasions that the imbalance violated the constitutional principle of one person-one vote. The Supreme Court mandated the addition of eight representatives to urban districts and the removal of seven from rural districts in 1986. Several lower house districts' boundaries were redrawn. Yet the disparity was still as much as three urban votes to one rural vote.

After the 1986 change, the average number of persons per lower house representative was 236,424. However, the figure varied from 427,761 persons per representative in the fourth district of Kanagawa Prefecture, which contains the large city of Yokohama, to 142,932 persons in the third district of largely rural and mountainous Nagano Prefecture.

The 1993 reform government under Hosokawa Morihiro introduce a new electoral system whereby 200 members (reduced to 180 beginning with the 2000 election) are elected by proportional representation in multi-member districts or "blocs" while 300 are elected from single-candidate districts.[12]

Still, according to the 6 October 2006 issue of the Japanese newspaper Daily Yomiuri, "the Supreme Court followed legal precedent in ruling Wednesday that the House of Councillors election in 2004 was held in a constitutionally sound way despite a 5.13-fold disparity in the weight of votes between the nation's most densely and most sparsely populated electoral districts".

The 2009 general House of Representatives election was the first unconstitutional lower house election under the current electoral system introduced in 1994 (parallel voting and "small" FPTP single-member electoral districts/"Kakumander"). In March 2011, the Grand Bench (daihōtei) of the Supreme Court ruled that the maximum discrepancy of 2.30 in voting weight between the Kōchi 3 and Chiba 4 constituencies in the 2009 election was in violation of the constitutionally guaranteed equality of all voters. As in previous such rulings on unconstitutional elections (1972, 1980, 1983 and 1990 Representatives elections, 1992 Councillors election), the election is not invalidated, but the imbalance has to be corrected by the Diet through redistricting and/or reapportionment of seats between prefectures.[13]

In 2016, a panel of experts proposed to introduce the [John Quincy] Adams apportionment method (method of smallest divisors) for apportioning House of Representatives seats to prefectures. The reform is planned to be implemented after the 2020 census figures are available and not expected to take effect before 2022.[14] In the meantime, another redistricting and apportionment passed in 2017 is designed to keep the maximum malapportionment ratio in the House of Representatives below 2. In the FPTP tier, it changes 97 districts and cuts six without adding any; in the proportional tier, four "blocks" lose a seat each; the total number of seats in the lower house is cut to 465, 289 majoritarian seats and 176 proportional seats.[15]

The malapportionment in the 2010[16] and 2013[17] regular House of Councillors elections was ruled unconstitutional (or "in an unconstitutional state") by the Supreme Court, and has been reduced by a 2015 reapportionment below 3 (at least in government statistics from census data which is regular and standardized but lags behind resident registration statistics and the actual number of eligible voters; using the latter, the maximum malapportionment in the 2016 election remained slightly above 3[18][19]).

The following table lists the 10 electoral districts with the highest and lowest number of registered voters per member elected for each chamber of the National Diet according to the voter statistics as of September 2016 released by the Ministry of Internal Affairs and Communications – it takes into account the lowering of the voting age and the district reforms to both houses of the Diet in effect since the 2014 and 2016 elections, but not the 2017 redistricting/reapportionment effective from the next House of Representatives election.

Prefectural assemblies and governors, as well as mayors and assemblies in municipalities, are elected for four-year terms. In April 1947, all local elections in the 46 prefectures (excluding Okinawa, then under US military rule) and all their municipalities were held at the same time in "unified local elections" (tōitsu chihō senkyo). Since then, some gubernatorial and mayoral elections, and most assembly elections, have stayed on this original four-year cycle. Most governors and mayors are now elected on different schedules as the four-year cycle "resets" upon the resignation, death or removal of a sitting governor or mayor. Some assembly election cycles have also shifted due to assembly dissolutions or mergers of municipalities. In the last unified local elections in April 2015, 10 of 47 governors, 41 of 47 prefectural assemblies, 222 mayors and 689 municipal assemblies were scheduled to be elected.

Upcoming elections due to expiring terms (additional early elections may be caused by resignations, deaths, votes of no confidence, dissolutions, recalls etc.):

• National elections
  • April 25, 2021: By- and repeat elections (hoketsu- & sai-senkyo) for vacant majoritarian seats in the National Diet as necessary – two majoritarian vacancies and one invalid election as of February 5, 2021: the Nagano seat in the 2019–25 class and one Hiroshima seat in the 2019–25 class of the House of Councillors, Hokkaidō 2 in the House of Representatives
  • Before autumn 2021 (end of term 2021/10/21): 49th general election of [all 465] members of the House of Representatives
  • Summer 2022 (end of term 2022/7/25): 26th regular election of [124] members of the House of Councillors
  • Summer 2025 (end of term 2025/7/28): 27th regular election of [the remaining 124] members of the House of Councillors
• Prefectural elections
  • Gubernatorial elections
    • 2021/1/24 (official announcement 1/7): Gifu (end of term 2/5),[21] Yamagata (end of term 2/13)[22]
    • 2021/3/21 (official announcement 3/4): Chiba (end of term 4/4)[23]
    • 2021/4/4 (official announcement 3/18): Akita (end of term 4/19)[24]
    • Rest of 2021: Shizuoka (end of term 7/4), Hyōgo (end of term 7/31), Ibaraki (end of term 9/25), Miyagi (end of term 11/20), Hiroshima (end of term 11/28)
  • Assembly general elections
    • 2021/7/4 (official announcement 6/25): Tokyo (end of term 2021/7/22)[25]
• Major municipal elections (designated major cities only)
  • Mayoral elections
    • 2021/4/25 (official announcement 4/11): Nagoya (end of term 4/27)[26]
    • 2021/5/23 (official announcement 5/9): Saitama (end of term 5/26)[27][28]
    • Rest of 2021: Chiba (end of term 6/13), Sendai, Yokohama, Kawasaki, Kōbe, Okayama
  • Assembly general elections
    • 2021/1/31 (official announcement 1/22): Kitakyūshū (end of term 2/9)[29]
    • 2021/3/28 (official announcement 3/19): Shizuoka (end of term 3/31)[30]

A used Japanese ballot paper from the 1952 House of Representatives election, in this case spoilt by writing "There is no suitable person" (該当者なし, Gaitō-sha Nashi). The only thing that is literally "on the ballot" in Japan before a voter votes is an empty box titled "candidate name" (候補者氏名, Kōho-sha Shimei) and usually a text next to it with general notes such as "Please don't write anything other than the name of an actual candidate." or "Please don't write outside the box."

A sample ballot paper for a House of Representatives election according to a 1945 Home Ministry ordinance

Votes in national and most local elections are cast by writing the candidate's or party's name on a blank ballot paper. In elections for the House of Representatives voters fill in two ballots, one with the name of their preferred district candidate and one with their preferred party in the proportional representation block. For the House of Councillors, the district vote is similar (in SNTV multi-member districts, several candidates can be elected, but every voter has only one vote). But in the proportional vote for the House of Councillors votes are cast for a party list (to determine how many proportional seats a party receives) or a candidate (which additionally influences which candidates are elected from a party's list).[31]

Ballots that cannot unambiguously be assigned to a candidate are not considered invalid, but are assigned to all potentially intended candidates proportionally to the unambiguous votes each candidate has received. These so-called "proportional fractional votes" (按分票, Anbun-hyō) are rounded to the third decimal.[32] For example, if "Yamada A" and "Yamada B" both stood in an election and there were 1500 unambiguous votes: 1000 for "Yamada A" and 500 for "Yamada B"; five ambiguous votes for "Yamada" would then count for Yamada A as 5×1000/1500=3.333 votes, and for Yamada B as 5×500/1500=1.667 votes.

In 2002, passage of an electronic voting law[33] allowed for the introduction of electronic voting machines in local elections.[34] The first machine vote took place in Niimi, Okayama in June 2002.[35] In 2003, a system for early voting (期日前投票制度, Kijitsu-mae tōhyō seido) was introduced.[36] In the 2017 general/House of Representatives election, a record number of more than 21 million Japanese voted early;[37] at the same time overall turnout was low (the second lowest in history), so in 2017, roughly 38 % of all actual voters had voted early. For regular/House of Councillors elections, the 2019 election set a new all-time high with more than 17 million early voters,[38] corresponding to roughly a third of actual voters in 2019 as overall turnout hit the second lowest value in history.

In Japan, walkovers in elections are called Mutōhyō tōsen (無投票当選), "[being] elected without vote". And there is literally no vote held in a walkover in Japan, no way to vote "no" or abstain explicitly: If there are only as many candidates in an election as there are seats/offices at the start of the legal election period ("official announcement": kōji (公示) in national general and regular elections; kokuji (告示) in prefectural and municipal elections as well as national by-elections), they are declared the winners. But the otherwise applicable moratorium period after regular elections on recall attempts does not apply after a walkover. (Recalls are a two-/three-step procedure: first, supporters of a recall must collect a sufficient number of signatures; if they do, a referendum is held on whether or not to recall the incumbent; only if that is accepted by a majority, a fresh election is scheduled.) Article 100 of the Public Offices Election Law deals with walkovers,[39] there are additional walkover provisions for subnational elections in the Local Autonomy Law.

Walkovers have become widespread in prefectural and municipal elections in recent years; in the 2019 unified local elections, out of 2277 seats up in 945 electoral districts for 41 prefectural assemblies, a record 612 seats are won by walkovers in a total of 371 districts or 39% of all electoral districts. In one extreme case, a rural single-member electoral district to the Shimane prefectural assembly, there hasn't been a contested election in 31 years (the whole Heisei period).[40][41]

• Electoral calendar
• Election
• Political funding in Japan
• Japanese Diet

• Adam Carr's Election Archive
• Daily Yomiuri Online: Inequality at the polls must be corrected
• (in Japanese) MIC: Elections, political funds
• Free Choice Foundation: Election system in Japan