Tsunekiyo of Watari District is said to be a descendant of FUJIWARA no Hidesato (TAWARA no Toda) from the Northern House of the Fujiwara clan, and his name appears as 'Tsunekiyo of Mutsu District' in "Zo Kofukuji Ki" (Records of the Construction of Kofuku-ji Temple), which lists the names of the Fujiwara clan who held the court rank equal to or higher than Goi (Fifth Rank).
なお、亘理経清は、藤原北家の藤原秀郷（俵藤太）の子孫とされており、1047年（永承2年）の五位以上の藤原氏交名を記した『造興福寺記』に、「経清六奥」（六奥は陸奥の意）と名前が見えている。