The Kutsuki clan was based in Kutsukidani-jo Castle, which served as hokoshu (a military post in the Muromachi Shogunate) for the Muromachi bakufu (a Japanese feudal government headed by a shogun) for generations.
朽木氏は朽木谷城を本拠として代々室町幕府奉公衆を務めた。