Hōjō Tokimasa
Though Masako may have sought to have Hiki formally accused of treason and executed, the Hōjō, under Hōjō Tokimasa, got to him first. In their schemes to dominate the regency and control the shogunate as a puppet government under their clan, Hōjō warriors assassinated Hiki Yoshikazu, and then attacked the palace of young Ichiman, setting a fire and killing both the young heir and a great number of members of the extended Hiki family.