Setsubun is a Japanese holiday which was the day before the beginning of spring in the old Japanese Imperial calendar.
Most years it falls on Februrary 3rd of the Gregorian calendar, but it can sometimes be on the day before or after the third; in 2021 and 2025 it fell on the second, for example.
It is associated with the practice of mamemaki, in which people throw roasted soybeans either out of their doors or at people dressed as oni before slamming the door.
This practice is not observed by some families with the surname Watanabe because of a legend involving Watanabe no Tsuna vanquishing the strongest oni. For more information, see the Wikipedia article. Also see