Japan is located in East Asia and consists of five island districts (Hokkaido, Honshu, Shikoku, Kyushu, and Okinawa), surrounded by the Pacific Ocean, the Sea of Japan, and the Sea of Ohotsuku. The total area is 377 835 sq. km (The World Factbook 2005). Honshu is the largest island with the capital, Tokyo. The climate varies from humid tropical in the south (Okinawa) to humid continental and cool summer in the north (Hokkaido). The climate of Honshu (the main island) is humid continental and warm summers. The official language is Japanese.