Uji (氏) are Japanese kin groups of the Kofun period. Uji were similar to the traditional Japanese clans; however, the pre-Taika uji did not have many of the characteristics which are commonly understood to be part of Japanese clans. For example, the Nakatomi clan and the Fujiwara clan were each uji. The uji was not only a social, economic and political unit. It also had religious significance in the 5th-7th centuries. The chief family has the title of Uji no kami.