Fukaya (深谷市, Fukaya-shi) is a city located in Saitama Prefecture, Japan. As of 1 January 2021[update], the city had an estimated population of 229,517 in 142,803 households in 60804 households and a population density of 1023 persons per km2.[1] The total area of the city is 138.37 square kilometres (53.42 sq mi). It is famous for a variety of welsh onions or Fukaya-negi (深谷ネギ). Fukaya is located on the northern border of Saitama Prefecture, in the flatlands of the Kantō plain, in-between the Tone River and the Arakawa River .