According to "Nihonshoki," Toyokiiruhiko no mikoto, who was a Prince of Emperor Sujin and ordered to rule Togoku, was the ancestor of Kamitsukenu no kuninomiyatsuko and Shimotsukenu no kuninomiyatsuko.
『日本書紀』によると、崇神天皇の皇子豊城入彦が東国統治を命じられ、上毛野国造や下毛野国造などの祖先になったという。