'Great new food festival'. A ritual undertaken by the new emperor at the beginning of his reign. It takes place within a temporary sacred compound at the imperial palace called the daijogu and follows the ceremony of accession (senso) and enthronement (sokui rei). The daijosai takes place at the first occurrence of the Niinamesai (new rice) ritual after the enthronement. First fruits are offered by the new emperor to his imperial ancestors including Amaterasu. A meal including boiled and steamed rice and sake is shared with the kami. The rice and wine derive from different fields (regions) entitled yuki and suki. The ritual is held in the building called the yukiden before midnight and again in the sukiden before dawn. One interpretation holds that the ritual honours the kami and that the emperor ingests strength and protection through the food. Another view is that the ceremony, which involves objects such as a cloak and couch, is a rite of passage, a kind of incubation of the new emperor, during which he is infused with the soul of Amaterasu.
A Popular Dictionary of Shinto. Brian Bocking.