Tozawa

The Tozawa were a warrior house of the Ou region, holding estates around Semboku and Kakunodate. Their genealogy claimed descent from Taira no Tadamasa: his grandson Hidemori is said to have submitted to Minamoto no Yoritomo in 1185 and taken the Tozawa name. Historians consider them more probably a local house, perhaps of Emishi stock.

Driven by Nanbu pressure, Kanemori moved to Dewa in 1206 and built Kadoya Castle in 1228. The Tozawa backed the Southern Court, sending troops under Gensei for Kitabatake Akinobu's campaign in 1341, before turning to the Northern Court in 1356.

They joined Toyotomi Hideyoshi's Odawara campaign in 1590. Tozawa Masamori sided with the Tokugawa at Sekigahara, but was reduced to forty thousand koku at Matsuoka. In 1622 the clan became lords of Shinjo Domain, which it ruled until the Meiji Restoration, later receiving a viscountcy.