Kamaishi is a city located on the Sanriku rias coast in Iwate Prefecture, Japan. As of 31 March 2020, the city had an estimated population of 32,609, and a population density of 74 persons per km2, in 16,230 households. The total area of the city is 441.43 square kilometres (170.44 sq mi)

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.