The theory insists that he was a child of the priest named Raien, a grandchild of the Imperial Prince Yorihito (the fourth son of Emperor Gotoba), who was exiled to Kojima, Bizen Province after the Jokyu War.
承久の乱の折、後鳥羽上皇の第四皇子・頼仁親王が備前国児島へと配流となり、その孫の僧・頼宴の子という説。