Officially called the Noboribetsu Onsen Hot Water Festival (Noboribetsu onsen yu matsuri), this unique festival takes place at the coldest time of year, when the last thing you want to be is naked (well, semi-naked) while running around at night and throwing water at each other. The all male participants split into two teams to do battle (mainly throwing hot water at each other) and then join together to carry around a large phallus mikoshi. You can find out more in our article about joining the festival.