A lot of demons exist in the Japanese folklore. They have usually a human body with frightening features like long claws or teeth, horns, blue or red skins, etc. Oni are generally feared but some are considered more like naughty imps. Oni are often found in Japanese literature, theater or art.
On the third day of February, Japanese celebrate the 'Setsubun', the lunar new year. On that day, they clean their houses and follow a special purifying ritual called 'Mamemaki' where they throw roasted beans in the house to send the Oni out and welcome luck.