National Diet

The National Diet (国会, Kokkai, kok̚.kai^[1]) is the national legislature of Japan. It is composed of a lower house, called the House of Representatives (衆議院, Shūgiin), and an upper house, the House of Councillors (参議院, Sangiin). Both houses are directly elected under a parallel voting system. In addition to passing laws, the Diet is formally responsible for nominating the prime minister. The Diet was first established as the Imperial Diet in 1890 under the Meiji Constitution, and took its current form in 1947 upon the adoption of the post-war constitution. Both houses meet in the National Diet Building (国会議事堂, Kokkai-gijidō) in Nagatachō, Chiyoda, Tokyo.

Composition

The houses of the National Diet are both elected under parallel voting systems. This means that the seats to be filled in any given election are divided into two groups, each elected by a different method; the main difference between the houses is in the sizes of the two groups and how they are elected. Voters are asked to cast two votes: one for an individual candidate in a constituency, and one for a party list. Any national of Japan at least 18 years of age may vote in these elections, reduced from age 20 in 2016.^[2][3] Japan's parallel voting system (mixed-member majoritarian) is not to be confused with the mixed-member proportional systems used in many other nations. The Constitution of Japan does not specify the number of members of each house of the Diet, the voting system, or the necessary qualifications of those who may vote or be returned in parliamentary elections, thus allowing all of these things to be determined by ordinary law. However it does guarantee universal adult suffrage and a secret ballot. It also stipulates that the electoral law must not discriminate in terms of "race, creed, sex, social status, family origin, education, property or income".^[4]

The election of Diet members is controlled by statutes passed by the Diet. This is a source of contention concerning re-apportionment of prefectures' seats in response to changes of population distribution. For example, the Liberal Democratic Party (LDP) had controlled Japan for most of its post-war history, and it gained much of its support from rural areas. During the post-war era, large numbers of people relocated to urban centers for economic reasons; though some re-apportionments have been made to the number of each prefecture's assigned seats in the Diet, rural areas generally have more representation than do urban areas.^[5] Among rural interests, Japanese rice farmers historically had particular influence in internal LDP politics and national policies on trade and agricultural subsidies.^[6]

The Supreme Court of Japan began exercising judicial review of apportionment laws following the Kurokawa decision of 1976, invalidating an election in which one district in Hyōgo Prefecture received five times the representation of another district in Osaka Prefecture.^[7][8] In the most recent elections, the malapportionment ratio amounted to 3.03 in the House of Councillors (2022 election: Kanagawa/Fukui)^[9] and 2.06 in the House of Representatives (2024 election: Hokkaidō 3/Tottori 1).^[10]

Candidates for the lower house must be 25 years old or older and 30 years or older for the upper house. All candidates must be Japanese nationals. Under Article 49 of Japan's Constitution, Diet members are paid about ¥1.3 million a month in salary. Each lawmaker is entitled to employ three secretaries with taxpayer funds, and to receive free Shinkansen tickets, and four round-trip airplane tickets a month to enable them to travel back and forth to their home districts.^[11]

Powers

Article 41 of the Constitution describes the National Diet as "the highest organ of State power" and "the sole law-making organ of the State". This statement is in forceful contrast to the Meiji Constitution, which described the Emperor as the one who exercised legislative power with the consent of the Diet. The Diet's responsibilities include not only the making of laws but also the approval of the annual national budget that the government submits and the ratification of treaties. It can also initiate draft constitutional amendments, which, if approved, must be presented to the people in a referendum. The Diet may conduct "investigations in relation to government" (Article 62).

The Prime Minister must be designated by Diet resolution, establishing the principle of legislative supremacy over executive government agencies (Article 67). The government can also be dissolved by the Diet if the House of Representatives passes a motion of no confidence introduced by fifty members of the House of Representatives. Government officials, including the Prime Minister and Cabinet members, are required to appear before Diet investigative committees and answer inquiries. The Diet also has the power to impeach judges convicted of criminal or irregular conduct.^[4]

In most circumstances, in order to become law a bill must be first passed by both houses of the Diet and then promulgated by the Emperor. This role of the Emperor is similar to the Royal Assent in some other nations; however, the Emperor cannot refuse to promulgate a law and therefore his legislative role is merely a formality.^[12]

The House of Representatives is the more powerful chamber of the Diet.^[13] While the House of Representatives cannot usually overrule the House of Councillors on a bill, the House of Councillors can only delay the adoption of a budget or a treaty that has been approved by the House of Representatives, and the House of Councillors has almost no power at all to prevent the lower house from selecting any Prime Minister it wishes. Furthermore, once appointed it is the confidence of the House of Representatives alone that the Prime Minister must enjoy in order to continue in office. The House of Representatives can overrule the upper house in the following circumstances:^[14]

• If a bill is adopted by the House of Representatives and then either rejected, amended or not approved within 60 days by the House of Councillors, then the bill will become law if again adopted by the House of Representatives by a majority of at least two-thirds of members present.^[15]
• If both houses cannot agree on a budget or a treaty, even through the appointment of a joint committee of the Diet, or if the House of Councillors fails to take final action on a proposed budget or treaty within 30 days of its approval by the House of Representatives, then the decision of the lower house is deemed to be that of the Diet.^[15]
• If both houses cannot agree on a candidate for Prime Minister, even through a joint committee, or if the House of Councillors fails to designate a candidate within 10 days of House of Representatives' decision, then the nominee of the lower house is deemed to be that of the Diet.

Activities

Under the Constitution, at least one session of the Diet must be convened each year. Technically, only the House of Representatives is dissolved before an election. But, while the lower house is in dissolution, the House of Councillors is usually "closed". The Emperor both convokes the Diet and dissolves the House of Representatives but in doing so must act on the advice of the Cabinet. In an emergency the Cabinet can convoke the Diet for an extraordinary session, and an extraordinary session may be requested by one-quarter of the members of either house.^[16] At the beginning of each parliamentary session, the Emperor reads a special speech from his throne in the chamber of the House of Councillors.^[17]

The presence of one-third of the membership of either house constitutes a quorum^[16] and deliberations are in public unless at least two-thirds of those present agree otherwise. Each house elects its own presiding officer who casts the deciding vote in the event of a tie. The Diet has parliamentary immunity. Members of each house have certain protections against arrest while the Diet is in session and arrested members must be released during the term of the session if the House demands. They are immune outside the house for words spoken and votes cast in the House.^[18][19] Each house of the Diet determines its own standing orders and has responsibility for disciplining its own members. A member may be expelled, but only by a two-thirds majority vote. Every member of the Cabinet has the right to appear in either house of the Diet for the purpose of speaking on bills, and each house has the right to compel the appearance of Cabinet members.^[20]

Legislative process

The vast majority of bills are submitted to the Diet by the Cabinet.^[21] Bills are usually drafted by the relevant ministry, sometimes with the advice of an external committee if the issue is sufficiently important or neutrality is necessary.^[22] Such advisory committees may include university professors, trade union representatives, industry representatives, and local governors and mayors, and invariably include retired officials.^[21] Such draft bills would be sent to the Cabinet Legislation Bureau of the government, as well as to the ruling party.^[21]

Building

History

Japan's first modern legislature was the Imperial Diet (帝国議会, Teikoku-gikai) established by the Meiji Constitution in force from 1889 to 1947. The Meiji Constitution was adopted on February 11, 1889, and the Imperial Diet first met on November 29, 1890, when the document entered into force.^[23] The first Imperial Diet of 1890 was plagued by controversy and political tensions. The Prime Minister of Japan at that time was General Count Yamagata Aritomo, who entered into a confrontation with the legislative body over military funding. During this time, there were many critics of the army who derided the Meiji slogan of "rich country, strong military" as in effect producing a poor country (albeit with a strong military). They advocated for infrastructure projects and lower taxes instead and felt their interests were not being served by high levels of military spending. As a result of these early conflicts, public opinion of politicians was not favorable.^[24]

The Imperial Diet consisted of a House of Representatives and a House of Peers (貴族院, Kizoku-in). The House of Representatives was directly elected, if on a limited franchise; universal adult male suffrage was introduced in 1925 when the Universal Manhood Suffrage Law was passed, but excluded women, and was limited to men 25 years or older.^[25] The House of Peers, much like the British House of Lords, consisted of high-ranking nobles chosen by the Emperor.^[26]

The first election by universal suffrage without distinction of sex was held in 1946, but it was not until 1947, when the constitution for post-war Japan came into effect, that universal suffrage was established In Japan.^[27]

The word diet derives from Latin and was a common name for an assembly in medieval European polities like the Holy Roman Empire. The Meiji Constitution was largely based on the form of constitutional monarchy found in nineteenth century Prussia that placed the king not as a servant of the state but rather the sole holder of power and sovereignty over his kingdom, which the Japanese view of their emperor and his role at the time favoured.^[28] The new Diet was modeled partly on the German Reichstag and partly on the British Westminster system. Unlike the post-war constitution, the Meiji constitution granted a real political role to the Emperor, although in practice the Emperor's powers were largely directed by a group of oligarchs called the genrō or elder statesmen.^[29]

To become law or bill, a constitutional amendment had to have the assent of both the Diet and the Emperor. This meant that while the Emperor could no longer legislate by decree he still had a veto over the Diet. The Emperor also had complete freedom in choosing the Prime Minister and the Cabinet, and so, under the Meiji Constitution, Prime Ministers often were not chosen from and did not enjoy the confidence of the Diet.^[26] The Imperial Diet was also limited in its control over the budget. However, the Diet could veto the annual budget. If no budget was approved, the budget of the previous year continued in force. This changed with the new constitution after World War II.^[30]

The proportional representation system for the House of Councillors, introduced in 1982, was the first major electoral reform under the post-war constitution. Instead of choosing national constituency candidates as individuals, as had previously been the case, voters cast ballots for parties. Individual councillors, listed officially by the parties before the election, are selected on the basis of the parties' proportions of the total national constituency vote.^[31] The system was introduced to reduce the excessive money spent by candidates for the national constituencies. Critics charged, however, that this new system benefited the two largest parties, the LDP and the Japan Socialist Party (now Social Democratic Party), which in fact had sponsored the reform.^[32] As a result of both the 2024 Japanese general election and the 2025 Japanese House of Councillors election, the LDP for the first time in party history failed to control either of the two houses in the National Diet.^[33]

List of sessions

There are three types of sessions of the National Diet:^[34]

• R – jōkai (常会), regular, annual sessions of the National Diet, often called "regular National Diet" (通常国会, tsūjō Kokkai). These are nowadays usually called in January, they last for 150 days and can be extended once.
• E – rinjikai (臨時会), extraordinary sessions of the National Diet, often called "extraordinary National Diet" (臨時国会, rinji Kokkai). These are often called in autumn, or in the summer after a regular election of the House of Councillors (参議院議員通常選挙, sangiingiin tsūjōsenkyo) or after a full-term general election of the House of Representatives (衆議院議員総選挙, shūgiingiin sōsenkyo). Its length is negotiated between the two houses, it can be extended twice.
• S – tokubetsukai (特別会), special sessions of the National Diet, often called "special National Diet" (特別国会, tokubetsu Kokkai). They are called only after a dissolution and early general election of the House of Representatives. Because the cabinet must resign after a House of Representatives election, the National Diet always chooses a prime minister-designate in a special session (but inversely, not all PM elections take place in a special Diet). A special session can be extended twice.
• HCES – There is a fourth type of legislative session: If the House of Representatives is dissolved, a National Diet cannot be convened. In urgent cases, the cabinet may invoke an emergency session (緊急集会, kinkyū shūkai) of the House of Councillors to take provisional decisions for the whole Diet. As soon as the whole National Diet convenes again, these decisions must be confirmed by the House of Representatives or become ineffective. Such emergency sessions have been called twice in history, in 1952 and 1953.^[35]

Any session of the National Diet may be cut short by a dissolution of the House of Representatives (衆議院解散, shūgiin kaisan). In the table, this is listed simply as "(dissolution)"; the House of Councillors or the National Diet as such cannot be dissolved.

List of House of Representatives general elections

19th century

20th century

21st century

List of House of Councillors regular elections

20th century

21st century

See also

• Bicameralism
• Diet (assembly)
• Government of Japan
• History of Japan
• List of legislatures by country
• List of members of the Diet of Japan
  • List of current members of the House of Representatives of Japan
  • List of current members of the House of Councillors
• National Diet Building
• National Diet Library
• Parliamentary system
• Politics of Japan
• 国会開会式 – Opening ceremony of National Diet

Notes

1. ^ * CDP (39) * Independent (1)
2. ^ * Independent (2)
3. ^ * Team Mirai (1) * Independent (1)
4. ^ * LDP (315) * Independent (1)
5. ^ * LDP (1/Speaker) * CRA (1/Vice Speaker) * Reiwa (1) * Genzei–Yukoku (1) * Independent (3)

References

1. ^ NHK Broadcasting Culture Research Institute (ed.) (24 May 2016). ja:NHK日本語発音アクセント新辞典 (in Japanese). NHK Publishing.
2. ^ "Diet enacts law lowering voting age to 18 from 20". The Japan Times. Archived October 10, 2016 at the Wayback Machine. Retrieved June 17, 2015.
3. ^ Japan Guide Coming of Age (seijin no hi) Archived March 2, 2012 at the Wayback Machine Retrieved June 8, 2007.
4. ^ National Diet Library. Constitution of Japan Archived October 7, 2011 at the Wayback Machine. Published 1947. Retrieved July 15, 2007.
5. ^ U.S. Library of Congress Country Studies Japan – Electoral System Archived October 12, 2011 at the Wayback Machine. Retrieved June 8, 2007.
6. ^ Wojtan, Linda S. (November 1993). "Rice: It's More Than Food In Japan". Stanford Program on International and Cross-Cultural Education. Retrieved December 4, 2024.
7. ^ The Judgement of the Supreme Court, January 14, 1976 (最大判昭51.1.14).
8. ^ Goodman, Carl F. (Summer 2001). "The Somewhat Less Reluctant Litigant: Japan's Changing View towards Civil Litigation". Law and Policy in International Business. 32 (4): 785. Archived August 4, 2020 at the Wayback Machine. Retrieved April 21, 2019.
9. ^ Asahi Shimbun, June 22, 2022: 2022年参院選、一票の格差は最大3.032倍　朝日新聞算出 Retrieved December 14, 2024.
10. ^ NHK, October 16, 2024: 衆議院選挙の「一票の格差」2倍以上に 前回の選挙に続き Retrieved December 14, 2024.
11. ^ Fukue, Natsuko, "The basics of being a lawmaker at the Diet Archived September 2, 2011 at the Wayback Machine", The Japan Times, January 4, 2011, p. 3.
12. ^ House of Councillors. Legislative Procedure. Published 2001. Retrieved July 15, 2007.
13. ^ Asia Times Online Japan: A political tsunami approaches. By Hisane Masaki. Published July 6, 2007. Retrieved July 15, 2007.
14. ^ "Diet | Japanese government". Encyclopedia Britannica. Archived November 19, 2017 at the Wayback Machine. Retrieved August 22, 2017.
15. ^ House of Representatives of Japan Disagreement between the Two Houses. Retrieved July 14, 2007.
16. ^ House of Representatives of Japan Sessions of the Diet. Retrieved July 14, 2007.
17. ^ House of Representatives of Japan Opening Ceremony and Speeches on Government Policy. Retrieved July 14, 2007.
18. ^ "Judgments of the Supreme Court Case 1994 (O) 1287". Supreme Court of Japan. Archived October 20, 2020 at the Wayback Machine. Retrieved August 13, 2020.
19. ^ "Judgments of the Supreme Court Case Number 1978 (O) 1240". Supreme Court of Japan. Archived October 20, 2020 at the Wayback Machine. Retrieved August 13, 2020.
20. ^ "The Constitution of Japan, CHAPTER IV THE DIET". Japanese Law Translation. Archived from the original on January 5, 2021. Retrieved August 12, 2020.
21. ^ Oda, Hiroshi (2009). "The Sources of Law". Japanese Law. Oxford University Press. doi:10.1093/acprof:oso/9780199232185.001.1. ISBN 978-0-19-923218-5. Archived June 3, 2018 at the Wayback Machine. Retrieved May 27, 2020.
22. ^ M. Nakamura and T. Tsunemoto, 'The Legislative Process: Outline and Actors', in Y.Higuchi (ed.), Five Decades of Constitutionalism in Japanese Society (Tokyo, 2001), pp. 197–219
23. ^ Fraser, Andrew; Mason, R. H. P.; Mitchell, Philip (September 16, 2005). Japan's Early Parliaments, 1890–1905: Structure, Issues and Trends. Routledge. p. 8. ISBN 978-1-134-97030-8. Archived January 22, 2023 at the Wayback Machine. Retrieved November 27, 2019.
24. ^ Stewart Lone Provincial Life and the Imperial Military in Japan Archived January 22, 2023 at the Wayback Machine. Page 12. Published 2010. Routledge. ISBN 0-203-87235-5
25. ^ Colegrove, Kenneth (1929). "Labor Parties in Japan". American Political Science Review. 23 (2): 329–363. doi:10.2307/1945218. ISSN 0003-0554. JSTOR 1945218. S2CID 145649163.
26. ^ House of Representatives of Japan From Imperial Diet to National Diet. Retrieved July 15, 2007.
27. ^ "THE CONSTITUTION OF JAPAN". japan.kantei.go.jp. Retrieved 2019-06-05.
28. ^ Hellegers, Dale M. (2001). We, the Japanese People: World War II and the Origins of the Japanese Constitution. Stanford: Stanford University Press. p. 234. ISBN 0804780323.
29. ^ Henkin, Louis and Albert J. Rosenthal Constitutionalism and Rights: the Influence of the United States Constitution Abroad. Page 424. Published 1990. Columbia University Press. ISBN 0-231-06570-1
30. ^ "Diet | Japanese government". Encyclopedia Britannica. Archived November 19, 2017 at the Wayback Machine. Retrieved November 2, 2020.
31. ^ Ministry of Internal Affairs and Communication. Chapter 27 – Government Employees and Elections Archived March 5, 2012 at the Wayback Machine. Published 2003. Retrieved June 8, 2007.
32. ^ Library of Congress County Data. Japan – The Legislature Archived June 24, 2007 at the Wayback Machine. Retrieved June 8, 2007.
33. ^ "Japan's Long-Dominant Party Suffers Election Defeat as Voters Swing Right". The New York Times. July 20, 2025.
34. ^ House of Councillors: 国会の召集と会期 Archived November 13, 2017 at the Wayback Machine
35. ^ House of Councillors: 参議院の緊急集会 Archived December 9, 2017 at the Wayback Machine
36. ^ House of Representatives: 国会会期一覧 Archived November 13, 2017 at the Wayback Machine, retrieved October 4, 2019.

External links

• National Diet Library: Diet and Parliaments has the Diet minutes and additional information (in Japanese) (archived 18 October 2002)