In Japan, February 3rd is called "Setsubun". That means "seasonal devision". There are four Setsubun a year. But usually the term refers to the Spring Setsubun. February 4th called "Risshun" is the begining of spring. In the old Japanese calendar, Risshun was the first day of the New Year. So Setsubun was the New Year's Eve and people participate in a bean-throwing ceremony to cleanse away the evil and bring luck for the next year.
In the ceremony, the toshiotoko (a man who born in the year with the same sign as the Chinese zoadic of the current year) or the male of household throws the roasted soybeans called fortune beans (fukumame) outside and inside of the house or one of the family members wearing a demon (Oni) mask. People say "Demons out! Luck in!" (Oni-wa-soto! Fuku-ha-uchi!).
Soybeans are thought that have magical powers that take away misfortune and diseases. On the other hand, it is said that you will get good luck if you eat the number of beans as your current age with one more additional bean.
Soybeans have a lot of nutrition, such as protein, fiber, vitamin B1, B2, iron and calcium. They contain an antioxidant called saponin that prevents lifestyle diseases and cancer. Miso, soy sauce, natto and tofu are made from soybeans.
There are other practices on Setsubun. You eat rolling sushi called "Eho-maki". That means "lucky direction roll". You eat the eho-maki facing the year's lucky compass direction, determined by the zodiac symbol of the year. You eat eho-maki silently and pray for luck of the next year. Ginger-sake is also drunk on Setsubun.