Mine is a city located in Yamaguchi Prefecture, Japan. As of 1 April 2023, the city had an estimated population of 21,919 in 10661 households …Mine is a city located in Yamaguchi Prefecture, Japan. As of 1 April 2023, the city had an estimated population of 21,919 in 10661 households and a population density of 46 persons per km². The total area of the city is 1,472.64 square kilometres.