Ōmisoka December 31

Traditionally, the important activities of the year and the end day were completed in order to start the new year smoothly. Some of these include cleaning the house, paying off debts, purifying (such as driving away evil spirits and bad luck) and bathing so that the last hours of the year could be spent relaxing.

In recent times, families and friends often gather for celebrations, including watching the Kōhaku Uta Gassen (紅白歌合戦, "Red/White Singing Battle") which lasts over four hours, or more recently to watch large mixed martial arts. This custom has its roots in the ancient Japanese culture surrounding toshigamisama (歳神様) or toshitokusama (歳徳様), which revolved around the practice of showing reverence to the gods of the current and future years.

About an hour before New Year's, people often gather for one last time in the previous year to have a bowl of toshikoshi soba or toshikoshi udon together—a tradition based on people's association of eating the long noodles with "the passing of one year to the next," which is the meaning of toshi-koshi.

While the noodles are often eaten plain or with chopped green onions, in some localities people top them with tempura. Traditionally, families prepare osechi in the last days of the year. The food is then eaten during the first days of the new year to "welcome the 'deity of the year' into each household" and "wish for happiness throughout the year."

At midnight, many visit a shrine or temple for Hatsumōde, or the first shrine/temple visit of the year. Throughout Japan, Shinto shrines prepare the amazake to vanish before the crowds that gather as midnight approaches. Most Buddhist temples have a large bonshō (Buddhist bell) that is struck once for each of the 108 earthly temptations believed to cause human suffering.

When seeing someone for the last time before the New Year, it is traditional to say "Yoi o-toshi wo" (良いお年を, lit. "Happy New Year"). The first traditional greeting after the New Year begins is "Akemashite omedetō (明けましておめでとう, lit. "Congratulations on the New Year").