Koga

Koga (古河市, Koga-shi) is a city located in Ibaraki Prefecture, Japan. As of 1 October 2020, the city had an estimated population of 138,446 in 56,097 households and a population density of 1120 persons per km². The percentage of the population aged over 65 was 28.98%. The total area of the city is 123.58 square kilometres (47.71 sq mi).