The Aoshima Naked Man Festival (青島裸参り)
On Coming of Age Day, when the air temperature hovers around 6°C at Aoshima, this ritual purification festival known as Aoshima Shrine Hadaka Mairi invites men and boys (and now women as well!) to plunge into the ocean waters wearing nothing more than loincloths (or robes for the ladies) and tabi socks.
The festival starts with taiko drumming as crowds of almost naked people at Aoshima Shrine wait to rush into the water. After stretching and getting ready, the courageous people charge into the ocean waters for a purifying dip.
As participants step out from the sea after their plunge, steam rises from their bodies due to the difference in temperatures between the air and the water.
After a few more dips and splashes and offering prayers at the shrine, the ceremony completed. Participants drink tea in a hot onsen bath, and then mochi is made.
It is possible to participate in this festival, but do keep in mind that spaces fill up very quickly. Inquire with the friendly staff at the shrine itself to find out when and how to register. You may need the help of a fluent Japanese speaker to make sure you register correctly.