Many immigrants called sakuto were sent from the Hokuriku and Kanto regions to these areas, which were under the ancient Japanese government, and which also served as a foothold for immigrants, an office for governance, and a site to hold banquets for subordinate barbarians who paid tributes to.
また、律令政府の配下に置かれたそれらの地域には北陸や関東から柵戸と呼ばれる多くの移民が送り込まれたが、それらの移民の拠点、支配するための官衙、配下に置いた俘囚（服属蝦夷）が朝貢したり、それに対する饗応をする役目も負っていた。