The National Diet Building (AFLO)
A plenary session of the Diet (House of Councillors)
Japan's Constitution, which came into force in 1947, is based on three principles: sovereignty of the people, respect for fundamental human rights, and renunciation of war. The Constitution also stipulates the independence of the three branches of government - legislative (the Diet), executive (the cabinet), and judicial (the courts).
The Diet, Japan's national parliament, is the highest organ of state power and the sole law-making organ of the state. The Diet comprises the 480-seat House of Representatives (lower house) and the 242-seat House of Councillors (upper house). All Japanese citizens can vote in elections once they reach the age of 20.
Japan has a parliamentary system of government like Britain and Canada. Unlike the Americans or the French, the Japanese do not elect a president directly. Diet members elect a prime minister from among themselves. The prime minister forms and leads the cabinet of ministers of state. The cabinet, in the exercise of executive power, is responsible to the Diet.
Judicial power lies with the Supreme Court and lower courts, such as high courts, district courts, and summary courts. The Supreme Court consists of a chief justice and 14 other justices, all of whom are appointed by the cabinet. Most cases are handled by district courts. There are also summary courts, which deal with problems like traffic violations. A lay judge system was introduced in May 2009. Under this system, six adult citizens (20 or over) are chosen at random to act as lay judges in criminal cases tried in district courts.
There are 47 prefectural and numerous municipal governments in Japan. Their responsibilities include providing education, welfare, and other services and building and maintaining infrastructure, including utilities. Their administrative activities bring them into close contact with local people. The heads of regional governments and local assembly members are chosen by local people through elections.