In what is known as one of the strangest festivals under the sun, participants wearing nothing but loincloths splash each other with hot water.

Event Dates	Every year on January 20
Event Details	Starts early at 5:00 a.m. on January 20, 2026 *See the official website for details.
Official site	http://www.kawarayu.jp/
Location (venue)	Kawarayu Onsen, in front of Oyu
Address	491-6 Kawarayu, Naganohara-cho, Agatsuma-gun, Gunma

Region	Kanto
Category	Bravery

Event organizers may change the date and time. Please check the official website.

update: Nov.18.2025