Mogami clan
The area of present-day was Tozawa part of ancient Dewa Province and during the Nara Period and early Heian period was an important fortified point on the road connecting Akita Castle on the Sea of Japan with Tagajo on the Pacific Ocean. During the Sengoku period, the area was under the control of the Mogami clan. During the Edo period, the village was a river port on the Mogami River. After the start of the Meiji period, the area became part of Mogami District, Yamagata Prefecture. The village of Tozawa was established on April 1, 1889 with the establishment of the modern municipalities system. It absorbed the neighboring villages of Furukuchi and Kadokawa in 1955.