Tsugaru clan
Oura Mitsunobu, the founder of the Tsugaru clan, settled in Tanesato (now part of Ajigasawa) in 1491, which developed into a port for the Tsugaru region. The area around Ajigasawa was controlled by the Tsugaru clan of Hirosaki Domain during the Edo period. Ajigasawa became a village in Nishitsugaru District, Aomori with the establishment of the modern municipalities system on April 1, 1889, and was elevated to town status on March 31, 1955 by annexing the neighboring villages of Akaishi, Nakamura, Narusawa and Maido.