One of the key figures of Kyoto’s Gion Matsuri is the Celestial Child (chigo in Japanese). The Celestial Child rides on the first float of the festival procession, the Naginata-Hoko, as pictured here. The Celestial Child is chosen in June and is purified by a Shinto priest from Yasaka Shrine. He plays an important role in several of the events of Gion Matsuri in early July, but his main duty is to start the Yama Boko Junko procession on July 17 by cutting a Shinto rope with a sword.
For those interested in learning more about Gion Matsuri in both photographs and words, I heartily recommend the book Kyoto Gion Festival. As far as I know, it is only available here in Japan, but it is very reasonably priced at 1,600 yen and has text in both Japanese and English. I do not know the author, but I wish I did!