The Ministries of Japan consist of eleven ministries and the Cabinet Office. Each ministry is headed by a Minister of State, which are mainly senior legislators, and are appointed from among the members of the Cabinet by the Prime Minister. The Cabinet Office, formally headed by the Prime Minister, is an agency that handles the day-to-day affairs of the Cabinet. The ministries are the most influential part of the daily-exercised executive power, and since few ministers serve for more than a year or so necessary to grab hold of the organisation, most of its power lies within the senior bureaucrats.