However, in those days it was a practice to install a member of the Imperial Family as the Empress because the Empress could ascend the throne as an interim emperor after the death of the Emperor (her husband) and therefore Nagayao opposed the installation of Komyoshi as the Empress.
しかしながら皇后は夫の天皇亡き後に中継ぎの天皇として即位する可能性があるため皇族しか立后されないのが当時の慣習であったことから、長屋王は光明子の立后に反対していた。