Government of Japan
The Current Emperor of Japan (今上天皇) is Akihito. He was officially enthroned on November 12, 1990. He is styled as "His Imperial Majesty" (天皇陛下), and his reign bears the era name of Heisei (平成). Naruhito, the Crown Prince of Japan, is the heir apparent to the Chrysanthemum Throne.
Emperor of Japan
Unlike most constitutional monarchs, the Emperor is not even the "nominal" chief executive. explicitly vests executive power in the Cabinet, of which the Prime Minister is the leader. The Emperor is also not the commander-in-chief of the Japan Self-Defense Forces. The Japan Self-Defense Forces Act of 1954 also explicitly vests this role with the Prime Minister.