Emperor Reizei had a mental illness which made him go mad and he was not granted a long reign; his younger maternal brothers, Imperial Princes Tamehira and Morihira, were seen as likely candidates for the Togu, and in the end the younger of the brothers, Imperial Prince Morihira, was chosen.
冷泉天皇は狂気の病があり、長い在位は望まれず、東宮には同母弟の為平親王、守平親王が有力だったが、年少の守平親王が東宮に選ばれた。