The Setsubun is a japanese tradition held on the 3rd of February, tomorrow.
Before the start of spring, japanese people have rituals in order to chase away devils or bad spirits, and ask good spirits to come in.
From the house (from the window or from the door), they throw roasted beans outside and say :
"Oni ha soto! Fuku ha uchi!"
"Devils are out! Happiness is in!"
As you could see on the picture, the red face represents devils, whereas the white face represents happiness and good spirits.
Usually, the father of the family put a red mask of the devil, and goes out after children throw beans on him. And the mother put the white mask which represents the good spirits than come.
After that, people should eat the number of beans corresponding to their age, so for example 5 beans for a five years old child, whereas his mother should eat 30 beans! In real life, children eat their corresponding age number of beans, but adults don't for various reasons (it is not good for health to eat too much beans, don't like it..).
In current days, because they don't like beans, instead of, some people prefer to throw wrapped chocolates, more pleasant to eat...