As Emperor Juntoku stated in the "Kinpisho" (a book written by Emperor Juntoku, which records the history and origin of the Imperial Court's ceremonies and sets forth the rules and etiquette for carrying out such ceremonies) that consideration should be given to divine service before other manners at the Imperial Court, successive emperors have given the highest priority to Shinto rituals since the establishment of the country.
順徳天皇が『禁秘抄』で「禁中作法先神事」と述べたように、天皇は肇国以来「神事」を最優先してきた。