The area of present-day Shōnai was part of ancient
Dewa Province. After the start of the
Meiji period, the area became part of
Higashitagawa District, Yamagata Prefecture. The town of Amarume was established on April 1, 1889, with the creation of the modern municipalities system, and the town of Karikawa on April 1, 1937. Karikawa merged with the neighboring villages of Kiyokawa and Tachiyazawa on October 1, 1954, and was renamed Tachikawa. On July 1, 2005, the towns of Tachikawa and Amarume merged to form the new town of Shōnai. ==Economy==