Born the child of Sessho (Regent) Yoshitsune KUJO and the older brother of Kanpaku (Chief Advisor to the Emperor) Michiie KUJO, it was said that Keisei became physically disabled due to a childhood accident and subsequently entered the priesthood at Enjo-ji Temple.
摂政九条良経の子息にして関白九条道家の兄に生まれながら、幼時の事故が身体に障害を来たしたといい、園城寺に入り出家。