When his nephew TAIRA no Masakado was attacked by ambushing MINAMOTO no Tasuku who was a son of Kunika's father-in-law, Mamoru and went on the counterattack on March 16, 935, Kunika was killed in a fire of his residence called Ishida-kan.
舅である護の子源扶に要撃された甥の平将門が、承平5年（935年）2月4日(旧暦)に反撃に出た際、居館の石田館が焼かれ死亡した。