Ogasawara clan
The , onetime ruling family of the Jōzai Domain, is a Japanese clan which traces its origins to the Ogasawara clan, the shugo of Shinano Province, and through the Takeda clan, from the Seiwa Genji. The family served the Matsudaira (later Tokugawa) clan from its days in Mikawa Province. It became a family of hatamoto under the Tokugawa shogunate; in 1825, upon receiving a raise in income to 10,000 koku (thanks to the family head Tadafusa, who was then a wakadoshiyori), the Hayashi family entered the ranks of the "daimyōs".