According to the temple history, the Futai-ji Temple was originally called 'Kaya no Gosho' (Thatched-Roofed Imperial Palace) where his grandfather, Emperor Heijo, took the tonsure and then retired to as a result of the Kusuko Incident.
寺伝によれば不退寺は、元は祖父の平城天皇が薬子の変により剃髪したのち隠棲した「萱の御所」であったとされる。