Setsubun ("seasonal division") is a festival held on February 3 or 4, one day before the start of spring according to the Japanese lunar calendar. Setsubun is not a national holiday.
For many centuries, the people of Japan have been performing rituals with the purpose of chasing away evil spirits at the start of spring.
Around the 13th century, for example, it became a custom to drive away evil spirits by the strong smell of burning dried sardine heads, the smoke of burning wood and the noise of drums. While this custom is not popular anymore, a few people still decorate their house entrances with fish heads and holy tree leaves in order to deter evil spirits from entering.
In modern days, the most commonly performed setsubun ritual is the throwing of roasted beans around one's house and at temples and shrines across the country. When throwing the beans, you are supposed to shout （鬼は外！服はうち！）Oni wa soto! Fuku wa uchi!" ("Devils out, happiness in"). Afterwards you should pick up and eat the number of beans, which corresponds to your age.
Another custom at the time of setsubun is to eat the number of beans corresponding to your age. News broadcasts and other television shows on February 3rd carry footage of Japanese sumo wrestlers and other celebrities who are 12, 24, 36, 48, 60, or even 72 years old standing outside well-known shrines throwing and/or eating dried soybeans. These celebrities were born under the same sign of the Asian zodiac (this year is the year of the ox) as the current year, and thus this year’s setsubun festival is especially auspicious for them.