According to Sonpi Bunmyaku (a text compiled in the fourteenth century that records the lineages of the aristocracy) and Utsunomiya family records, it is said that he had a son, FUJIWARA no Soen, who became the founder of the Utsunomiya clan.
また尊卑分脈や宇都宮系図などによると、兼房の子に藤原宗円がおり宇都宮氏の祖となったとされる。