The Saidaiji Eyō (西大寺会陽), more commonly known as the Hadaka Matsuri (“Naked Festival”), gets more international media attention than most Japanese festivals. The festival, which has a history dating back more than 500 years, sees almost 10,000 men, dressed only in a white loincloths, scramble and grapple for a small wooden stick. It is held each year on the third Saturday in February.
The male participants enter the temple in the evening to purify their bodies in cold water. They stand in the cold air until 10pm when the lights are turned off and a pair of wooden (shingi) are thrown by a priest into the crowd from a ledge above. For the next two hours, the men jostle and push to be one to carry one of these two sticks out of the temple, and, in doing so, be blessed with luck for the year.
While the shingi are the main object of desire, about 100 other objects that bring good fortune are tossed into the crowd. Most participants go there as groups, either friends participating for the experience or colleagues representing one of the local companies. Foreign visitors are able to join in the festival, but must register beforehand. And, of course, the wearing of a loincloth is a must. See here for the registration process (Japanese only). In March 2016, Saidaiji Eyo was designated a national important intangible folk cultural property.