Making efforts toward recovery of the "chogi and kuji" (political operations and ceremonies of the Imperial Court) as kugyo of the Northern Court which the Shogun Ashikaga family supported, Yoshimoto became the Kanpaku of Emperor Komyo and the Toshi choja (chieftain of the Fujiwara family) in 1346.
足利将軍家が擁する北朝の公卿として朝儀・公事の復興に努め、1346年には光明天皇の関白・藤氏長者となる。