Motoharu MORI, a great-grandson of Tokichika, supported the Ashikaga side during the period of the Northern and Southern Courts, and played an active role under the commander Sadayo (Ryoshun) IMAGAWA, when the Ashikaga bakufu (Muromachi bakufu) dispatched Sadayo for the subjugation of Seiseifu fortress in Kyshu, which was under the power of Southern Court governed by the Imperial Prince Kanenaga.
南北朝時代には足利方に従い、時親の曾孫にあたる毛利元春は、足利幕府(室町幕府)が九州の南朝勢力であった懐良親王の征西府を討伐するために派遣した今川貞世(了俊)の指揮下に入り活躍している。