Tokyo (東京, Tōkyō; "Eastern Capital"^?), officially Tokyo Metropolis (東京都, Tōkyō-to^?), is the capital and largest city of Japan, and is one of the 47 prefectures of Japan. It is located on the eastern side of the main island Honshū. Tokyo's government also administers the twenty-three special wards of Tokyo, each governed as a city, that cover the area that was once the city of Tokyo in the eastern part of the prefecture.

The population of the special wards is over 8 million people, with the total population of the prefecture exceeding 12 million. The prefecture is the center of the Greater Tokyo Area, 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.

Shinjuku (新宿区, Shinjuku-ku^?) is one of the 23 special wards of Tokyo, Japan. It is a major commercial and administrative center, housing the busiest train station in the world (Shinjuku Station) and the Tokyo Metropolitan Government Building, the administration center for the government of Tokyo.

As of 2008, the ward has an estimated population of 312,418 and a density of 17,140 persons per km². The total area is 18.23 km².

Shinjuku has the highest numbers of registered foreign nationals of any community in Tokyo. As of October 1, 2005, 29,353 non-Japanese with 107 different nationalities were registered in Shinjuku.^{[citation needed]}