Japan is a constitutional monarchy with a parliamentary government.
Under the constitution, Japan has universal adult suffrage with a secret ballot for all elective offices. The government consists of an executive branch responsible to the legislative branch and an independent judicial branch. Executive power is vested in a cabinet composed of a prime minister and ministers of state, all of whom must be civilians. The prime minister must be a member of the Diet, usually the lower house, and is designated by his colleagues. The prime minister has the power to appoint and remove ministers, a majority of whom must be Diet members.