Ōshū is a city located in Iwate Prefecture, Japan. As of 30 April 2020, the city had an estimated population of 114,620 and a population density of 120 persons per km2 in 45,728 households. The total area of the city is 993.30 square kilometres (383.52 sq mi). Ōshū is famous for its Maesawa Beef, numerous festivals, historic temples and shrines and Fujiwara no Sato, a theme park and movie lot based on the exploits of the Northern Fujiwaras in the 12th century. Many famous people claim Ōshū as their home, including Ichiro Ozawa, the long-time leader of the Democratic Party of Japan.

Iwate Prefecture is a prefecture of Japan located in the Tōhoku region of Honshu. It is the second-largest Japanese prefecture at 15,275 square kilometres (5,898 sq mi), with a population of 1,165,886. Iwate Prefecture borders Aomori Prefecture to the north, Akita Prefecture to the west, and Miyagi Prefecture to the south.