An old legend tells the story of the deity Iwahashi Myojin cultivating rice with the help of a wild boar. The combination of the characters for “boar” (猪) and “bed for rice seedlings” (苗代), hence “Inawashiro” (猪苗代). An alternative theory finds the word to have its origin in the language of the Ainu people, but in any case it points to a deep connection with the cultivation of rice. Present day Inawashiro owes its form to a large-scale eruption of the Mt. Bandai and Mt. Nekoma volcanoes that occurred between 40,000 and 50,000 years ago. There are also indications that the area around Lake Inawashiro was already inhabited by indigenous peoples 12,000 years ago. Especially in the southeast base area of the mountain facing the lake, ruins from the Jomon and Paleolithic/Pre-Jomon periods are still visible. The ruins that have been found in the bottom of the lake in the Nagahama, Kanisawahama and Sanjogata areas have been dated back to the Jomon and Kofun periods.