Japan's Emperor Naruhito (centre) walking towards Yukiden, one of the two Daijokyu halls built inside the East Gardens of the Imperial Palace in Tokyo's Chiyoda ward, for the Daijosai, or Great Thanksgiving, ceremony yesterday. Emperor Naruhito was to perform an elaborate and secretive ritual dating back 1,300 years, giving thanks to the Sun Goddess Amaterasu as part of his enthronement rites. The Daijosai, considered the most important ritual in Japan's imperial tradition and performed only once in an emperor's reign, comes three weeks after Emperor Naruhito proclaimed his ascension to the Chrysanthemum Throne.