• 1878 — The Minamiuwa District broke off from the
Uwa District through
Meiji era land reforms. (7 villages) • February 11, 1923 — The village of Mishō gained town status. (1 town, 6 villages) • February 11, 1923 — The village of Jōhen gained town status. (2 towns, 5 villages) • November 3, 1948 — The village of Uchiumi broke up into Uchiumi and Minamiuchiumi, with some parts merging into Jōhen. (2 towns, 6 villages) • April 1, 1952 — The village of Higashisotoumi gained town status. (3 towns, 5 villages) • September 1, 1952 — The village of Midorisōzu merged into the town of Jōhen. (3 towns, 4 villages) • October 1, 1952 — The village of Nishisotoumi was renamed and gained town status to become the town of Nishiumi. (4 towns, 3 villages) • September 21, 1956 — The town of Higashisotoumi merged into the town of Jōhen. (3 towns, 3 villages) • September 30, 1956 — The village of Minamiuchiumi merged into the town of Mishō. (3 towns, 2 villages) • January 1, 1962 — The village of Ipponmatsu gained town status. (4 towns, 1 village) • October 1, 2004 — The towns of
Ipponmatsu,
Mishō,
Jōhen and
Nishiumi, and the village of
Uchiumi merged to form the new town of
Ainan. (1 town) == References ==