The 23 city wards (ku) are the center of Tokyo and make up about one third of the metropolis' area, while housing roughly eight of Tokyo's approximately twelve million residents. Tokyo is also one of Japan's 47 prefectures, but is called a metropolis (to) rather than a prefecture (ken). The metropolis of Tokyo consists of 23 city wards (ku), 26 cities, 5 towns and 8 villages, including the Izu and Ogasawara Islands, several small Pacific Islands in the south of Japan's main island Honshu. The 23 city wards (ku) are the center of Tokyo and make up about one third of the metropolis' area, while housing roughly eight of Tokyo's approximately twelve million residents. Tokyo is also one of Japan's 47 prefectures, but is called a metropolis (to) rather than a prefecture (ken). The metropolis of Tokyo consists of 23 city wards (ku), 26 cities, 5 towns and 8 villages, including the Izu and Ogasawara Islands, several small Pacific Islands in the south of Japan's main island Honshu.