Kai is a city located in Yamanashi Prefecture, Japan. As of 31 December 2021, the city had an estimated population of 73,626, and a population density of 1,100 persons per km². The total area of the city is 71.95 square kilometres (27.78 sq mi).

Kōfu is the capital city of Yamanashi Prefecture, Japan. As of 1 April 2019, the city had an estimated population of 187,985 in 90,924 households, and a population density of 880 persons per km2. The total area of the city is 212.41 square kilometres (82.01 sq mi).