He accompanied his father , Yorimasa , and brother , Nakatsuna , in opposing the Taira clan .
Kanetsuna participated in the first Battle of Uji in 1180 that opened the Genpei War .
Kanetsuna accompanied Kanetsuna 's father , Yorimasa , and brother , Nakatsuna , in opposing the Taira clan .
Kanetsuna participated in the first Battle of Uji in 1180 that opened the Genpei War .