Ōmisoka is observed on December 24, 2021. ?misoka (New Year's Eve) is the second-most important day in Japanese tradition because it is the final day of the old year and the eve of New Year's Day, which is the most important day of the year. Around 11:00 pm on Ōmisoka at home, people often gather for one last time in the old year to have a bowl of toshikoshi-sobaor toshikoshi-udon together - a tradition based on people's association of eating the long noodles with “crossing over from one year to the next,” which is the meaning of toshi-koshi. While the noodles are often eaten plain, or with chopped scallions, in some localities people top them with tempura.
Traditionally, families make Osechi for new year day because cooking during the first 3 days of the new year is considered unlucky. Nowadays, most families buy Osechi or cook ordinary dishes. Throughout Japan, Shinto shrines prepare amazake to pass out to crowds that gather as midnight approaches. Most Buddhist temples have a large cast bell that is struck once for each of the 108 earthly desires believed to cause human suffering. (With material from: Wikipedia)