Honma

The Honma were warrior lords of Sado Island, descended from a family named for Honma in Sagami Province. They entered Sado as deputy governors under the Ōbutsu and held Sawada Castle, while branches established themselves at Kawarada and Hamochi.

In 1510 the Sawada and Hamochi branches helped Nagao Tamekage defeat Uesugi Akisada in Echigo. Rivalries later divided the family, and Uesugi Kagekatsu invaded Sado in 1589, defeating the Honma and taking Hamochi Castle.