His smooth promotion is mainly attributed to his connection with FUJIWARA no Koretada, who assumed Sessho (Regent) who had a maternal relationship with the emperor, and the connection was brought by Korenaka's grandmother FUJIWARA no Genki (the daughter of FUIWARA no Sugane and the legal wife of TAIRA no Tokimochi), who worked in the Imperial Court as a court lady and served to foster both Emperor Rezei and Enyu in their childhood.
順調な出世の背景には祖母の藤原元姫（藤原菅根の娘・中納言平時望室）が、女官として宮中に出仕して冷泉天皇・円融天皇両天皇の養育係を務めていた経歴によって、外戚である時の摂政藤原伊尹との関係を持ったことが大きいとされている。