In 1337, when Munehisa who was in Kyoto and heard of his father, Hisanaga, at his hometown being attacked by the Southern Court, he asked Takauji through Sadahisa to let him return home.
延元2/建武4年（1337年）、京都にいた宗久は国許の父、久長が南朝方に攻撃を受けたことを聞き、貞久を通じて尊氏に帰国させてくれるよう願い出る。