Sakai is a city located in Fukui Prefecture, Japan. As of 10 May 2018, the city had an estimated population of 92,210 in 31,509 households an…Sakai is a city located in Fukui Prefecture, Japan. As of 10 May 2018, the city had an estimated population of 92,210 in 31,509 households and a population density of 550 persons per km. The total area of the city was 209.67 square kilometres.