Having great affection for First Imperial Prince Koretaka (whose mother was a daughter of KI no Natora), and due to his concerns that Imperial Prince Korehito was too young, Emperor Montoku thought of enthroning Imperial Prince Koretaka first and then having Korehito take over when he was older but the Emperor passed away in 858 while he was procrastinating out of consideration for Yoshifusa.
文徳天皇は第一皇子惟喬親王（母は紀名虎の娘）を愛し、惟仁親王が幼すぎることを案じて、まず惟喬親王を立て、惟仁親王の成長の後に譲らせることを考えたが、良房を憚って決しないうちに天安(日本)2年（858年）に崩御してしまった。