The Aoi Matsuri, or “Hollyhock Festival,” is one of the main Shinto festivals of Kyoto. The procession itself is held annually on the 15th of May. For several days before the procession, shrine rites occur, including the purification of the young woman chosen as the Saio-Dai of the year.
Originally a royal princess would have been chosen, but now it is always a young unmarried lady of Kyoto.
She dresses in traditional Heian period clothing, decorated with aoi [hollyhock] leaves.
The festival originated to appease the Deities, after a terrible drought.
The original role of Saiō-Dai was to maintain ritual purity and to represent the Emperor at the festival.