This is a traditional naked festival in which men dressed in sarashi loin cloths carry a portable shrine across the sea. The festival dates back about 400 years, when a plague struck the area and yamabushi (mountain priests) went into the sea to purify themselves in order to ward off the evil plague. After Shinto rituals at the shrine, 29 men carry a vermilion-lacquered portable shrine weighing about 150 kilograms and enter the sea from the embankment near Kotsu-fukae Port with the call "Yoiya, Yoiya". They swim about 300 meters while men with conch shells lead the way from the shore. This event is held every year on the 20th of January during the "Daikan (Great Cold)" period, and although there is usually bad weather such as cold winds and snow, the men who reach the shore then visit around 80 parishioners' houses with the portable shrine. The shrine parishioners place namasu (a dish of raw fish and vegetables seasoned in vinegar) on the portable shrine and pour sake over it to pray for good health.