Then, Tamekiyo OKI defected from the Amago Remnant Corps, and they suffered defeat in the Battle of Fubeyama, which resulted in a remarkable decline in their power, bringing about the fall of Niyama-jo Castle, their last foothold, in August 1571.
その後は隠岐為清の離反を招き、布部山の戦いに敗北すると衰勢著しく、元亀2年（1571年）8月には最後の拠点であった新山城が落城する。