In 1037, when the Imperial Princess Teishi (later, Yomeimonin) was selected as the socond consort (later, Empress) for the Emperor Gosuzaku, Yoshinobu was appointed to the chugu daibu (a master of the place of the second consort of the emperor) who was a close aide to the chugu.
1037年（長元10年）、後朱雀天皇の中宮（後に皇后）に禎子内親王（後の陽明門院）が決まると、その側近である中宮大夫に任じられる。