Due to a brilliant tactic of Motonari, Naonobu KURATA, an uncle of the castle lord (Fusanobu KURATA), switched to the Amago clan, and Fusanobu KURATA, the castle lord, committed suicide before Kagamiyama Castle fell to Tsunehisa.
元就は策略を使い、城主蔵田房信の叔父、蔵田直信を寝返らせ、城主の蔵田房信は自害し、鏡山城は落城した。