오슈 후지와라 씨
The area of present-day Onagawa was part of ancient Mutsu Province, and has been settled since at least the Jōmon period by the Emishi people. During later portion of the Heian period, the area was ruled by the Northern Fujiwara. During the Sengoku period, the area was contested by various samurai clans before the area came under the control of the Date clan of Sendai Domain during the Edo period, under the Tokugawa shogunate.