After returning to Kyoto, he informed Tokiwa Gozen of Yoshitomo's death and thereafter, he entered the priesthood as a priest of Saikon-do of Kofuku-ji Temple in order to pray for Yoshitomo and called himself Shoshun TOSANOBO.
そして、京都に戻り常盤御前に義朝の死を知らせた後、義朝の菩提を弔うために出家し、興福寺西金堂の衆徒となり、土佐坊昌俊と号した。