Prince Tokiyasu's mother was FUJIWARA no Takushi, a daughter of FUJIWARA no Futatsugu, and she was also a sister of Mototsune's mother, Otoharu, making Mototsune a cousin of the Prince Tokiyasu.
時康親王の母は藤原総継の娘・藤原沢子で、基経の母・乙春とは姉妹であり、基経は時康親王の従兄弟にあたる。