Description Tokyo, officially Tokyo Metropolis, is one of the 47 prefectures of Japan. It is located on the eastern side of the main island Honshū and includes the Izu Islands and Ogasawara Islands. Tokyo Metropolis was formed in 1943 from the merger of the former Tokyo Prefecture and the city of Tokyo. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of Japan. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family.The Tokyo Metropolitan government administers the twenty-three special wards of Tokyo, each governed as a city, that cover the area that was the city of Tokyo as well as 39 municipalities in the western part of the prefecture and the two outlying island chains. The population of the special wards is over 8 million people, with the total population of the prefecture exceeding 13 million. The prefecture is part of the world's most populous metropolitan area with 35 to 39 million people (depending on definition) and the world's largest metropolitan economy with a GDP of US$1.479 trillion at purchasing power parity in 2008, surpassing even New York City, which ranks second on the list.