Koshigaya(越谷市,Koshigaya-shi) is a city located in Saitama Prefecture, in the central Kantō region of Japan. As of 1 February 2016, the city had an estimated population of 337,071 and a population density of 5,610 persons per km². Its total area was 60.24 square kilometres (23.26 sq mi). It is famous for producing daruma dolls.