After assuming the post of Kanrei with support of the anti-Shiba faction including Doyo SASAKI and Norisuke AKAMATSU, Yoriyuki counseled the third shogun Yoshimitsu ASHIKAGA who was only 11 years old on his appointment, helping establish Yoshimitsu's authority as shogun by ensuring he was promoted through the official rankes, making arrangements his education and training as a court noble, and constructing his new residence, Hana no Gosho (literally, the Flower Palace).
管領となった頼之は、佐々木道誉や赤松則祐をはじめ反斯波氏派の支持を得て、就任当時11歳の3代将軍足利義満を補佐し、官位の昇進、公家教養、将軍新邸である花の御所の造営など将軍権威の確立に関わる。