Tokyo, officially Tokyo Metropolis, is the capital city of Japan and one of its 47 prefectures. The Greater Tokyo Area is the most populous metropolitan area in the world. It is the seat of the Emperor of Japan and the Japanese government. Tokyo is in the Kantō region on the southeastern side of the main island Honshu and includes the Izu Islands and Ogasawara Islands. Formerly known as Edo, it has been the de facto seat of government since 1603 when Shōgun Tokugawa Ieyasu made the city his headquarters. It officially became the capital after Emperor Meiji moved his seat to the city from the old capital of Kyoto in 1868; at that time Edo was renamed Tokyo. Tokyo Metropolis was formed in 1943 from the merger of the former Tokyo Prefecture and the city of Tokyo.

After "The Moment," Tokyo made the most conscious effort out of all of the world, and the rest of Japan, to try and integrate and accept the travelers from another world. It has even gone so far as to host several festivals a year that used to belong to the Terrans that occupy Japan.