In the middle of the Heian period, people began to recognize that the ritual was mainly for deifying "Amaterasu Omikami" (the Sun Goddess), and in the cloistered emperor's reign, the recognition became more common, and Kinen-sai festival began to be conducted solemnly by the emperor to deify Amaterasu Omikami.
平安時代中頃になると、天照大神を主に祀る祭祀であると認識が変化しはじめ、院政期にはその傾向がさらに強くなり、祈年祭は天照大御神を奉祀する天皇の祭祀として厳修されるようになった。