Dontosai is an annual winter festival held (this year is on January 14) at Oosaki Hachimangu Shrine, Sendai City, Miyagi Prefecture, Japan.
Its main features is hundreds of people performing hadakamairi (naked pilgrimage), where they wearing only white plain clothes under freezing winter temperature (this time it’s -2 degrees celcius), and a giant bonfire where people will throw old new year decorations, and then pray for family’s health and safety throughout the new year.
AloJapan.com