During the period between the eighth century and the ninth century there were many changes made in the hereditary titles; this change was geared to the people with the lower social position who were excluded from the rank of higher hereditary position in the Yakusa no Kabane Reform as well as these peasants.
8～9世紀において改賜姓がさかんに行われているのは、八色の姓において、上級の氏姓にもれた下級の身分の者や、これらの農民を主な対象としたものである。