Kokushi were appointed from central government on an alternate basis as mikotomochi (a court official dispatched to a provincial post by imperial order) of the emperor, and were responsible for governing the province by serving as commanders of gunji (district managers).
国司は、中央から天皇のミコトモチ（御言持）として交替で赴任し、郡司を指揮して国内の支配に当たった。