origins were often claimed back to imperial princes.

Although the clans closest to the Imperial House, that is, descendants of Emperor Keitai, were intended to be promoted to Mahito, the first rank in the original eight kabane system, this fell out of favor with the nobility. In 802, Prince Yasuyo, a son of Emperor Kammu was designated Yoshimine no Ason Yasuyo, an indication that he had renounced his imperial status