During the late Heian period, kokushi became influential in the provincial government and assumed the authority to decide shoekimenjo (exemption of miscellaneous taxes) on Arata (also referred to as Areta; rice field of low grade) and the like.
平安時代後期に入ると、地方統治における国司の権限は強力となり、荒田などの諸役免除などを決定する権限を保持するようになる。