Politics of Japan

In Japan, politics are conducted in a framework of a dominant-party bicameral parliamentary representative democratic constitutional monarchy. A hereditary monarch, currently Emperor Naruhito, serves as head of state while the Prime Minister of Japan, currently Sanae Takaichi since 2025, serves as the elected head of government.

Legislative power is vested in the National Diet, which consists of the House of Representatives and the House of Councillors. The House of Representatives has eighteen standing committees ranging in size from 20 to 50 members and The House of Councillors has sixteen ranging from 10 to 45 members.

Executive power is vested in the Cabinet, which is led by the Prime Minister who is nominated by National Diet and appointed by the Emperor. A Liberal Democratic minority government has held office since 2025.

Judicial power is vested in the Supreme Court and lower courts, and sovereignty is vested in the people of Japan by the 1947 Constitution, which was written during the Occupation of Japan primarily by American officials and had replaced the previous Meiji Constitution. Japan is considered a constitutional monarchy with a system of civil law.

The Japanese politics in the post-war period has largely been dominated by the ruling Liberal Democratic Party (LDP), which has been in power almost continuously since its foundation in 1955, a phenomenon known as the 1955 System. Of the 32 prime ministers since the end of the country's occupation in 1952, 25 as well as the longest serving ones have been members of the LDP. Consequently, Japan has been described as a de facto one-party state. The LDP lost its parliamentary majority in 2024, but continues to lead the country as part of a minority government.

Japan is currently a "full democracy" in the Democracy Index with the highest V-Dem electoral and liberal democracy scores in Asia.

The current constitution was approved by Japan in 1947, this document aimed to address the weaknesses of the previous Meiji Constitution and lay the foundation for a vibrant democracy in Japan. Its key features include:

The creation and ratification of this current document has been widely viewed by many geopolitical analysts and historians as one that was forced upon Japan by the United States after the end of World War II.