The process of how and when Muramune succeeded to the family headship is not clear because there were few historical materials about the movement of Sukemune and Muramune in the beginning of the Eisho era, although Muramune is thought to become a head of the Uragami clan by succeeding Sukemune URAGAMI, an adopted heir of Norimune,
則宗の養嗣子である浦上祐宗の跡を継いで浦上氏の当主になったと見られるものの、肝心の家督相続の経緯、時期については永正年間前半の祐宗、村宗の動向を示す史料が少ない為、はっきりしない。