I've heard about this before, the Hadaka Matsuri (the Naked Festival), but never knew when or where or any of the details. If you look here you can find a nice English explanation.
Basically, from late Saturday (this year it was February 17th) evening thousands of men gather in tents near the Saidaiji Temple's grounds to don their fundoshi. They also get free drinks, run around to keep warm, and take part in ritual purifying baths.
That has GOT to be cold. Wait a minute! I think I see a non-Japanese in that picture! Several even!
At eleven PM everyone runs over to the main temple and hangs out for an hour. And by 'hanging out' I mean chanting and working themselves into a frenzy. When midnight arrives the lights are turned off and several shingi (sacred sticks) are dropped into the crowd of up to ten thousand naked, wet, and extremely boisterous men. The fight ensues.
It looks like the happy fellow below has got himself one of the shingi.Here is what the shingi look like when kept in the Shrine. It is very lucky if you manage to get one.
Here is an idea of what the crowd looks like. And some more pictures.
I just found a couple more beliefs surrounding the festival.
①If a pregnant woman wraps a fundoshi worn by one of the men who participated in the festival around her waist, she will have a safe delivery and a healthy child.
②If the dirt that has been tracked into the temple is sprinkled in a field, that field will produce a bumper crop.
③And finally, every man who participates in the event will not catch a cold for an entire year.
So, where will I be next year, the third weekend in February? Yep. Okayama Prefecture. Saidaiji. Maybe.