|Parliament name (generic / translated)
||Kokkai / National Diet
|Structure of parliament
|Chamber name (generic / translated)
||Shugiin / House of Representatives
|Related chamber (for bicameral parliaments)
Sangiin / House of Councillors
||15 April 1950
Last amendment: 19 June 2015
|Mode of designation
||directly elected 475
||- 295 single-member constituencies (majority system)*
- 11 multimember (6 to 29 seats) constituencies (proportional representation system) for 180 seats*
*In accordance with amendments to the Electoral law, promulgated on 27 May 2016, the number of single-member constituencies will decrease to 289, and the number of members elected under the proportional system will decrease to 176. The new House of Representatives will thus comprise a total of 465 members (down from 475). In accordance with article 1 of the supplementary provisions to the amendments, these reductions will be implemented once a separate law to revise the electoral districts has been adopted. In case general elections are held before that law comes into effect, the House of Representatives will continue to comprise 475 members.
- simple majority vote in 295 single-member constituencies
- party list under the proportional representation system using the d'Hondt method for the remaining 180 seats, with allocation of seats based on the parties' share of the national vote in the 11 large districts.
Candidates may run in both the single-seat constituencies and the proportional representation poll. However, these so called "duplicate" candidates are only allowed to run for the proportional representation block in which their single- seat constituency is located.
Each party's proportional representation list includes candidates who take part in the proportional representation poll alone, adding up to the set number of seats for each bloc plus duplicate candidates from single-seat constituencies.
Candidates running in single-seat constituencies must obtain at least one-sixth of all valid votes to obtain a seat.
Vacancies for members elected under the proportional representation system are filled by the "next-in-line" candidate of the same party, regardless of the number of votes obtained. However, in the case of duplicate candidates, the number of votes obtained must be higher than the statutory number of votes, i.e. one-tenth of all valid votes.
By-elections are held if seats occupied by members elected from single-seat-constituencies become vacant. They are held twice a year, in April and October.
Voting is not compulsory.
||- age: 18 years*
- Japanese citizenship
- domicile registered in a constituency for at least three months
Japanese nationals living abroad, who fulfil the following conditions and are registered on the electoral commission's overseas voters' list of the final place of residence in Japan can vote in general and parliamentary elections:
- Persons who have notified their town hall of a change in their location and of final residence in Japan;
- Persons who have been registered at the Japanese Embassy/Consulate as a Japanese citizen living abroad for at least three months (or those who can prove their residence over the past three months).
*On 4 and 17 June 2015 respectively, the House of Representatives and the House of Councillors adopted a bill to amend the Public Offices Election Act, which includes a provision to lower the voting age from 20 to 18 years old. The Act was promulgated by the Cabinet on 19 June 2015 and will be applied to national elections the start of whose campaign period is announced one year after that date (i.e., any election with a campaign period announced after 20 June 2016 and whose polling day falls after 7 July 2016).
The following persons are disqualified from voting:
- Persons recognized as a ward of the court by a family court;
- Persons sentenced to imprisonment or a more severe form of punishment and who have not completed their sentences;
- Persons sentenced to imprisonment or a more severe form of punishment and to whom the sentence still applies (excluding persons for whom execution of the sentence is suspended);
- Persons sentenced to imprisonment or to a more severe form of punishment for an electoral offence, and who are given suspended sentences;
- Persons who, during their tenure as public office-holders, were convicted of bribery. This disqualification is valid during the term of the sentence and for five years thereafter;
- Persons who have committed an election-related offence provided for in the Public Offices Election Act;
- Persons who have committed an offence provided for in the Public Funds Control Act.
||- Qualified electors
- age: 25 years
- Japanese citizenship
Ineligibilities: Persons who, during their tenure as public office-holders, have been convicted of bribery. This disqualification is valid during the term of the sentence and for five years thereafter.
||- official post in Government or local public entity
- officer or staff of public corporation
- a member may, during his term of office, be appointed as a member of a commission, adviser, counsellor or hold any other function of a similar nature in any executive branch of the Cabinet, based on a concurrent decision of both Houses
||- deposit of 3 million yen in single-seat constituencies, forfeited if the total number of votes obtained is less than 10 per cent of the total number of valid votes.
- deposit of 6 million yen for each candidate on the list of a political party, or 3 million yen if that candidate is also running for a single-seat constituency, forfeited according to the formula given below.
Amount to be forfeited = deposited amount - (3 million yen × A + 6 million yen × B × 2)
(a) A is the number of candidates who run for office in both a single-seat constituency and under the proportional representation system, and who are elected in the single-seat constituency;
(b) B is the number of candidates elected by proportional representation.