Nagai

The Nagai of Dewa were a gokenin house founded by Tokihiro, second son of Oe no Hiromoto. Tokihiro took his name from Nagai manor in Okitama, and after his elder brother Chikahiro was ruined in the Jokyu War of 1221, the Nagai inherited the main Oe lineage's standing.

They served the Hojo regents as shugo of Bingo and Tango. In the Hoji War of 1247 Yasuhide fought for the Hojo and helped save his Mori kinsmen's stewardships, a service later Mori daimyo remembered. The family built Yonezawa Castle and served as stewards of Nagai manor.

When the shogunate collapsed in 1333, Hirohide and his nephew Takafuyu joined Emperor Go-Daigo and then Ashikaga Takauji. Their long absence let the Date grow stronger: Date Muneto invaded Okitama in 1380, and in 1385 Date Masamune seized Nagai manor, reducing the clan to a minor local house.