The reason why he was called 'Sudo dayu' was the following: On the family tree, when FUJIWARA no Kimikiyo went back to Kyoto with his son who was born when he had been in charge of Zuryo (the head of the provincial governors) in the Kanto region, they met the Moribe clan who was Gunji (local magistrates) of the Mushiroda County in the Mino Province.
「守藤太夫」と呼ばれるのは系図上は藤原公清が関東の受領を務めていたときに出来た子を伴い、京に戻る途中で、美濃国席田郡司守部氏に会った。