In 1155, Yasutsune was appointed as Saemon-no-shoi (one of the government posts) as well as kebiishi (the police and judicial chief) and, in addition, was appointed as Kurodo to the new Emperor Goshirakawa who ascended the throne that year.
久寿2年（1155年）左衛門少尉・検非違使となり、またこの年即位した新帝・後白河天皇の蔵人に任ぜられる。