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).

Chōsei is a village located in Chiba Prefecture, Japan. As of 31 December 2020, the village had an estimated population of 14,028 in 6096 households and a population density of 500 persons per km². The total area of the village is 28.32 square kilometres (10.93 sq mi). It is the only remaining municipality classed as a village in Chiba Prefecture.