Katsushika is a special ward in the Tokyo Metropolis in Japan. It is known as Katsushika City in English. As of May 1, 2015, the ward has an es…Katsushika is a special ward in the Tokyo Metropolis in Japan. It is known as Katsushika City in English. As of May 1, 2015, the ward has an estimated population of 444,356, and a population density of 12,770 people per km². The total area is 34.80 km².