On the other hand, the written letters inscribed on the iron sword, which was excavated from the Okadayama Tumulus in Matsue City, Shimane Prefecture, "Nukatabe-no-Omi (chief of Nukatabe group)" indicated that bemin sei (a political naming system of the Yamato sovereignty) was enforced in the middle of the sixth century.
島根県松江市岡田山古墳から出土の鉄刀銘「額田部臣（ぬかたべのおみ）」からは、6世紀の中頃には部民制の施行を知ることが出来る。