In 1579, the Nanjo clan broke away from the Mori clan to the Oda clan, then Motoharu KIKKAWA (Motoharu MORI) opposed this action and invaded the Hoki province; although Motokiyo and his elder brother Mototsugu attacked Yabase-jo Castle of Mori side in two wave attacks, both were repulsed.
天正7年（1579年）に南条氏が織田氏の下へ離反し、翌天正8年（1580年）に吉川元春が伯耆へ侵出した際には兄の元続とともに八橋城を2波に渡って攻撃するも敗退した。