He was promoted to Sangi (councilor) on June 13, 990, and, in that year, his father-in-law, Kaneie, died and after his biological father, Michitaka, succeeded Kaneie, Michiyori was placed in adverse circumstances.
正暦元年（990年）5月13日(旧暦)に参議に昇進するも、この年に養父・兼家が薨去して実父・道隆が後を継ぐと不遇に置かれる事になる。