Isa

The Isa were a warrior family of Isa district in Hitachi Province, related to the Date. After fighting for Minamoto no Yoritomo in the 1189 Ōshū campaign, Isa Tamemune remained in Hitachi while relatives settled in Date district.

During the Northern and Southern Courts conflict, Isa Yukisuke supported the Southern Court and defended Isa Castle alongside nearby allies. The castle fell in 1343, and the family declined as the Date also lost their influence in Hitachi.