Hachiōji is a city located in the western portion of the Tokyo Metropolis, Japan. As of 31 March 2021, the city had an estimated population of 561,344, and a population density of 3,000 persons per km2. The total area of the city is 186.38 km2. It is the most populous city in Tokyo outside of the special wards. In 2015, it was designated as a core city for the first time in Tokyo. It was the second first city in Tokyo Prefecture to implement the municipal system after Tokyo City.