A year later, when Takauji was defeated by the Southern Court (Japan) and fled to Kyushu, the Shimazu family was ordered to subjugate the Southern Court power of Satsuma and Osumi, and Munehisa made military exploits under Sadahisa's lead.
翌年南朝(日本)方に破れ尊氏が九州に落ち延びてくると、島津一族は薩摩・大隅の南朝勢力の討伐を命じられ、宗久は貞久指揮の下軍功をあげる。