Hadaka Matsuri means, literally, “naked festival”. The young men who participate are naked except for traditional white loincloths known as fundoshi. Sometimes the participants in Hadaka Matsuri immerse themselves in a river beforehand to purify themselves. Occasionally several semi-naked young men will carry a mikoshi, or portable shrine, in the form of a horse, rice bale, or sake barrel into the river with them. Discuss
Source: The Free Dictionary