It's just a small custom that pops around at this time of year. The head of the household will don an
Oni mask and-- as he is running outside-- be pelted with soybeans by the other family members as they chant 鬼は外、福は内! (
oni wa soto, fuku wa uchi! Demon(s) out, good luck in!) It's sort of a ritual purification mixed with good family fun.
Not a lot else to it, really. Play along if you get the chance.
High time to finish what I've started. || Anki vocabulary drive: 5,000/10k. Restart coming soon. || Dig my
Road to Katakana tutorial on the App store.