Why do people throw roasted beans and shout at a demon on February 3rd?
On setsubun (around Feb 3), families and shrines throw roasted soybeans shouting 'Oni wa soto, fuku wa uchi' (demons out, luck in), eat beans equal to their age, and many eat an uncut ehomaki sushi roll facing a lucky direction.
Setsubun marks the old lunar-calendar turn from winter to spring; bean-throwing is a purification rite to drive out misfortune, later boosted by shrine events and retail promotion of ehomaki.
Why — five layers
Purification (harai) and the idea of expelling impurity/misfortune at a seasonal boundary underpin scattering beans to cleanse the home.
Setsubun originally marked the eve of risshun (start of spring) in the traditional calendar, when new-year-style boundary rituals were common.
The now-nationwide ehomaki custom was heavily spread by convenience-store and supermarket marketing from the 1990s onward, not ancient tradition.
International view
Rituals to expel bad luck at year/season boundaries exist widely, but the specific combo of bean-throwing, age-counted eating, and silent directional sushi-eating is uniquely Japanese.
But not always
Ehomaki is a recent commercial invention, not a national tradition, and many households now skip messy bean-scattering or use packaged individual portions.
What to do
You'll see beans and ehomaki everywhere in late January–Feb 3; grab a bag of fukumame to join in, and eat beans equal to your age (some add one for the year ahead).
Sources
- folklore studies of setsubun/mamemaki
- ehomaki commercial-history reporting