The National Diet is the sole law-making organ of the State based on the Constitution promulgated in 1946. The Diet comprises two houses: The House of Representatives (the lower house) and the House of Councillors (the upper House). The House of Representatives, whose members are elected for a four-year term by a combination of a single-seat constituency system and proportional representation. The Lower House may be dissolved at any time by the Emperor on the advice of the Prime Minister. The House of Councillors (the Upper House), whose members are elected for a six-year term – every three years, half of the Upper House members are elected.
Japan is a parliamentary cabinet system, and more than half of the cabinet members are selected from MPs by the Prime Minister. The Prime Minister is elected by MPs through a resolution of the Diet. MPs and the Cabinet are qualified to submit bills, and all the bills are passed to a committee for deliberation, which sometimes includes open hearings. After the committee votes on the bill, it is passed for approval to the Diet plenary session in both houses. If the two chambers’ votes are at odds, a conference committee is convened in an attempt to reach a compromise. After a law is passed, it is promulgated by the Emperor and announced in the government gazette. The Diet also has the authority to approve the budget, ratify treaties and amend the Constitution.