For five nights in early February, the fishing town of Owase — pressed between steep mountains and a deep ria inlet on the Kii Peninsula — becomes a collision. Men in white surge through the streets and slam into one another, shoulder against shoulder, roaring 'Yaya! Yaya!' — the cry that gives the festival of Owase Shrine its everyday name. Then, in the middle of winter, they walk into the sea. The rite of purification called kori-kaki sends them into the February water, and when they climb out, steam rises off their bodies into the night air. Owase is one of the rainiest towns in Japan, a place of fish and weather and little pretension, and its festival keeps the unpolished force of something maintained for the town rather than performed for visitors. That is worth respecting: come as a guest, stand a little back, and the five days will let you in anyway. The heat is real, and it is shared. For one week, the coldest month in this rain-soaked port becomes, by common effort, its warmest.