The Japanese political process has three types of elections: general elections to the House of Representatives held every four years (unless the lower house is dissolved earlier), elections to the House of Councillors held every three years to choose half of its members, and local elections held every four years for offices in prefectures and municipalities. Elections are supervised by Election Administration Commissions at each administrative level under the general direction of the Central Election Management Council, an extraordinary organ attached to the Ministry of Internal Affairs and Communications (MIC). The minimum voting age in Japan's non-compulsory electoral system was reduced from twenty to eighteen years in June 2016. Voters must satisfy a three-month residency requirement before being allowed to cast a ballot.
For those seeking offices, there are two sets of age requirements: twenty-five years of age for admission to the House of Representatives and most local offices, and thirty years of age for admission to the House of Councillors and the prefectural governorship. Each deposit for candidacy for national election is 3 million yen (about 27 thousand dollars) for a single-seat constituency and 6 million yen (about 54 thousand dollars) for proportional representation.
General elections of members of the House of Representatives (, Sh?gi-in giin s?-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 (, j?fuku rikk?ho) 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 (, ratio of margin of defeat) system determines the order of candidates.
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 (, Sangi-in giin ts?j?-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 constituences, 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 (, 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" (, tokutei-waku). In the 2019 election, almost all parties continued to use completely open lists; exeptions 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".
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 (?, 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-t?sen (, 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 (, Jiy?-Minshu-t?) 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 (, Shin-Jiy?-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 (, 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 Ichir? 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 (, Nihon-Shakai-t?). The 2009 House of Representatives elections handed the first non-LDP victory to the Democratic Party of Japan (, Minshu-t?).
Between 1885 and 1947 in the Empire of Japan, the prime minister was not elected, but responsible to, chosen and appointed by the Emperor. In practice, the Genr? () usually nominated a candidate for appointment. The Imperial Diet (?, Teikoku-gikai) and its elected lower house, the House of Representatives, which were set up in 1890 according to the Imperial Constitution, had no constitutionally guaranteed role in the formation of cabinets.[better source needed]
Since 1947, the Prime Minister has been chosen in the "designation election of the prime minister" (?, Naikaku s?ridaijin shimei senkyo) in the National Diet. It is held after a cabinet has submitted its resignation - the outgoing cabinet remains as caretaker cabinet until the Imperial inauguration ceremony of a new prime minister -; a cabinet must resign en masse under the constitution (Articles 69 and 70) 1. always on convocation of the first Diet after a general election of the House of Representatives, 2. if the post of prime minister has fallen vacant - that includes cases when the prime minister is permanently incapacitated, e.g. by illness, kidnapping or defection -, or 3. if a no-confidence vote in the House of Representatives is not answered by the dissolution of the chamber. Though both Houses of the Diet vote in two-round elections to select a prime minister, the House of Representatives has the decisive vote: If the two Houses vote for different candidates (as they did in 1948, 1989, 1998, 2007 and 2008), a procedure in the joint committee of both houses (, Ry?in Ky?gikai) may reach a consensus; but eventually the candidate of the House of Representatives becomes that of the whole Diet and thereby prime minister-designate. The designated prime minister must still be ceremonially appointed by the Emperor in the Imperial Investiture (, Shinnin-shiki) to enter office; but unlike some heads of state, the Emperor has no reserve power to appoint anyone other than the person elected by the Diet.
In 2001, LDP president and Prime Minister Junichir? Koizumi instituted an advisory council to investigate the possibility of introducing direct popular election of the prime minister in a constitutional revision.
The October 27 by-election in Saitama to fill the vacancy created by Motohiro ?no's (DPFP) resignation was won by previous governor and former DPJ House of Representatives member Kiyoshi Ueda who had been an independent since his move from national to prefectural politics in 2003. The only other candidate was Takashi Tachibana for the anti-NHK party.
The LDP lost both April 2019 by-elections, in Okinawa to the left opposition, in Osaka to the Ishin no Kai.
|Parties||Constituency||PR Block||Total seats|
|Liberal Democratic Party (LDP)||26,719,032||48.21||0.11||218||18,555,717||33.28||0.17||66||284||6||61.08||0.02|
|Constitutional Democratic Party of Japan (CDP)||4,852,097||8.75||New||18||11,084,890||19.88||New||37||55||40||11.83||6.66|
|Japanese Communist Party (JCP)||4,998,932||9.02||4.28||1||4,404,081||7.90||3.47||11||12||9||2.58||1.84|
|Social Democratic Party (SDP)||634,719||1.15||0.36||1||941,324||1.69||0.77||1||2||0||0.43||0.01|
|Kib? no T? (Party of Hope)||11,437,601||20.64||New||18||9,677,524||17.36||New||32||50||7||10.75||1.25|
|Nippon Ishin no Kai (JIP)||1,765,053||3.18||4.98||3||3,387,097||6.07||9.65||8||11||3||2.37||0.58|
|The third coalition||13,202,654||23.82||-||21||13,064,621||23.43||-||40||61||10||13.12||1.83|
|Happiness Realization Party (HRP)||159,171||0.29||-||0||292,084||0.52||0.03||0||0||0||0.00||0.00|
|New Party Daichi||-||-||-||-||226,552||0.41||-||0||0||0||0.00||0.00|
|No Party to Support||-||-||-||-||125,019||0.22||0.02||0||0||0||0.00||0.00|
|Party for Japanese Kokoro (PJK)||-||-||-||-||85,552||0.15||2.50||0||0||0||0.00||0.00|
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.
Still, according to the October 6, 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 (daih?tei) of the Supreme Court ruled that the maximum discrepancy of 2.30 in voting weight between the K?chi 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.
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. 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.
The malapportionment in the 2010 and 2013 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).
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.
|House of Representatives||House of Councillors|
|Lowest vote weight||Highest vote weight||Lowest vote weight||Highest vote weight|
|#||District||Registered voters||District||Registered voters||District||Registered voters
per member elected
per member elected
|1||Tokyo 1||514,974||Fukushima 4||233,491||Saitama||1,015,543||Fukui||328,772||1|
|2||Hokkaid? 1||505,510||Miyagi 5||234,373||Niigata||978,686||Saga||346,727||2|
|3||Tokyo 3||504,929||Kagoshima 5||240,056||Miyagi||975,466||Yamanashi||353,402||3|
|4||Tokyo 5||498,903||Tottori 1||240,874||Kanagawa||951,735||Kagawa||417,082||4|
|5||Hy?go 6||492,173||Nagasaki 3||242,165||Tokyo||937,470||Wakayama||419,011||5|
|6||Tokyo 6||490,674||Tottori 2||242,194||Osaka||915,000||Akita||448,236||6|
|7||Tokyo 19||488,494||Nagasaki 4||242,303||Nagano||885,638||Toyama||452,822||7|
|8||Tokyo 22||486,965||Aomori 3||244,007||Chiba||871,110||Miyazaki||466,829||8|
|9||Saitama 3||483,014||Mie 4||244,825||Gifu||850,190||Yamagata||475,419||9|
|10||Tokyo 23||481,206||Iwate 3||246,272||Tochigi||827,368||Ishikawa||481,027||10|
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" (t?itsu chih? 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.
As of 2015, the major contests in the unified local elections are as follows:
|Prefecture||Governor||Assembly||Designated city races|
Although Tokyo's metropolitan governor and assembly elections are currently held on separate schedules, 21 of the 23 special wards of Tokyo follow the unified election schedule for their assembly elections, the only exceptions being Katsushika and Adachi. The majority of Tokyo's special wards follow separate cycles for their mayoral elections. Tokyo elected its governor as part of the unified elections until 2011, but was forced to hold a 2012 election and 2014 election due to the resignations of Shintaro Ishihara and Naoki Inose.
Upcoming elections due to expiring terms (additional early elections may be caused by resignations, deaths, votes of no confidence, dissolutions, recalls etc.):
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).
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" (, Anbun-hy?) are rounded to the third decimal. 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 allowed for the introduction of electronic voting machines in local elections. The first machine vote took place in Niimi, Okayama in June 2002. In 2003, a system for early voting (?, Kijitsu-mae t?hy? seido) was introduced. In the 2009 Japanese general election, a record number of more than 10 million Japanese voted early.
In Japan, walkovers in elections are called Mut?hy? t?sen (), "[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": k?ji () in national elections; kokuji () in prefectural and municipal 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, 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).