It is said that Yoichi had no offspring, but there is hearsay (the Echigo-Nasu clan) claimed by the historian Yoshisada NASU, according to which, after Yoichi gave up the family estate and left home due to conflicts with the Kajiwara clan, he stayed with the Igarashi family in Echigo Province, got married and had a son (thus establishing himself as an ancestor of the Echigo-Nasu clan) and a daughter.
子孫についてはいないとされているが、歴史学者の那須義定などが主張する異説（越後那須氏）もあり、梶原氏といさかいをおこしたため家督を捨てて出奔し、越後国の五十嵐家に身を寄せ、結婚して一男一女をもうけ（息子は越後那須氏の祖となる）たという。