日本の自衛隊における最高位の階級は何？
The "Chief of Staff, Joint Staff", a four star Admiral or General, is the highest-ranking military officer in the Japan Self-Defense Forces, and is the head of the Operational Authority over the Japan Self-Defense Forces, executing orders of the Minister of Defense with directions from the Prime Minister. The "Chief of Staff, Joint Staff" supervises the service branches operations, and would assume command in the event of a war, but his or her powers are limited to policy formation and defense coordination during peacetime.
Chief of Staff, Joint Staff