Shinagawa is a special ward in the Tokyo Metropolis in Japan. The Ward refers to itself as Shinagawa City in English. The Ward is home to te…Shinagawa is a special ward in the Tokyo Metropolis in Japan. The Ward refers to itself as Shinagawa City in English. The Ward is home to ten embassies. As of 1 April 2016, the Ward had an estimated population of 380,293 and a population density of 16,510 persons per km². The total area is 22.84 km².