The Kuzu (国栖・国巣・国樔) were a people of ancient Japan believed to have lived along the Yoshino River in Shikoku. They were mentioned in the Kojiki and Nihon Shoki. They were also a population living in the old Hitachi province (today's Ibaraki Prefecture) mentioned by the Hitachi Fudoki.
They are believed to have spoken a language related to Ainu or other Jomon people and may have lent their name to the kudzu plant.
References
Kuzu Wikipedia(Text) CC BY-SA