 Ushishir had no permanent habitation prior to European contact, but was visited in summer by the Ainu tribes from Rasshua, who regarded the island as a sacred land, which they identified as the home of the thunder god.Remains of Ainu huts have been found on the northern slopes of Yankicha’s crater bay.Claimed by the Empire of Russia, sovereignty over Ushishir was passed to the Empire of Japan per the Treaty of Saint Petersburg along with the rest of the Kuril Islands.