Chiba clan
The area around Tōnoshō has been inhabited since at least the Japanese Paleolithic, and archaeologists have found stone tools and tombs from the Kofun period. During the Kamakura and Muromachi periods, the area was under control of the Chiba clan. After the start of the Edo period, much of the area of Tōnoshō was part of Omigawa Domain, a minor feudal domain under the Tokugawa shogunate.