Tagajō is a city located in Miyagi Prefecture, Japan. As of 1 June 2020, the city had an estimated population of 62,869 in 27,869 households, an…Tagajō is a city located in Miyagi Prefecture, Japan. As of 1 June 2020, the city had an estimated population of 62,869 in 27,869 households, and a population density of 3,200 people per km². The total area of the city is 19.64 square kilometres. The city was named after Taga Castle, the capital of Mutsu Province from the Nara period.