Honorary titles: Daijo Tenno or Jun Daijo Tenno (quasi ex-emperor) were conferred on the crown prince who did not ascend to the throne and the Emperor's father who stayed as the imperial prince.
皇位につかなかった皇太子、或いは天皇の実父ながら親王の身位に留まる皇族などに対して、しばしば太上天皇或いは准太上天皇の尊号が贈られた。