Mutsuzawa is a town located in Chiba Prefecture, Japan. As of 1 December 2020, the town had an estimated population of 6,928 in 2796 households and a population density of 190 persons per km². The total area of the town is 35.59 square kilometres (13.74 sq mi).

Isumi is a city located in Chiba Prefecture, Japan. As of 1 November 2020, the city had an estimated population of 37,206 in 17,004 households and a population density of 240 persons per km2. The total area of the city is 157.44 square kilometres (60.79 sq mi).