Ōmisoka is the Japanese name for New Year's Eve, the final day of the traditional year.
It is one of Japan's most important annual observances. Families commonly clean their homes, prepare special food, and complete year-end tasks before midnight. The cleaning custom, often called Ōsōji, symbolically clears away the old year's dirt and disorder.
Many people eat toshikoshi soba, or “year-crossing noodles,” on Ōmisoka. The long noodles are associated with longevity, while their easy breakability can symbolize leaving hardships behind. At Buddhist temples, joya no kane bells are rung 108 times as the old year ends.
Ōmisoka should not be confused with Shōgatsu, which refers to the New Year period beginning January 1. The distinction matters because one term names the year's final day, while the other covers the celebrations that follow.