The current Japanese constitution was promulgated in the year 1946 during the occupation by the Allied powers:
The Emperor does not have any effective power but is only the symbol of the state.
Legislature: The Japanese parliament is called the Diet. It consists of the House of Representatives and the House of Councillors. The members of the Diet are elected by the Japanese people.
Executive: The cabinet is headed by the Prime Minister. The cabinet further consists of the ministers which are appointed by the prime minister and are usually members of the Diet. The prime minister is elected by the Diet.
Judiciary: The highest court is the Supreme Court. Other courts are district courts, high courts, family courts, and summary courts. Judges are appointed by the cabinet.
Elections: The minimum voting age is 20 years. Women received the right to vote with the postwar constitution. Elections for the House of Representatives are carried out every four years, and half of the House of Councillors is elected every three years. Beside the national elections there are prefectural and municipal elections.
Defense: The constitution prohibits Japan to maintain military forces and to lead war. Despite the anti-war clause, the National Police Reserve was established in 1950 during the occupation of Japan by the Allied powers (1945-1952) as a replacement for American troops sent to the Korean War. The National Police Reserve was transformed into the Self Defense Force by the Japanese government in 1954.