Japan's first modern legislature was the 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. 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. The Imperial Diet consisted of a House of Representatives and a . 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. The House of Peers, much like the British
House of Lords, consisted of high-ranking nobles chosen by the Emperor. 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. 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. 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. 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. 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. 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. 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. File:The First Japnese Diet Hall 1890-91.jpg|The First Japanese Diet Hall (1890–91) File:National Diet Hiroshima Temporary Building (external view).jpg|National Diet Hiroshima Temporary Building (1894) File:The Second Japnese Diet Hall 1891-1925.jpg|The Second Japanese Diet Hall (1891–1925) File:National Diet in 1930s.jpg|National Diet Building (1930) File:National_Diet_Building_P5030133.jpg|National Diet Building (2017) == List of sessions ==