blue demon; blue ogre
A demon or ogre with blue skin, often depicted with horns. In folklore and modern media, blue oni are frequently paired with red oni (赤鬼).
During Setsubun, people sometimes wear red and blue demon masks.
A kind-hearted blue ogre appears in the old tale.
Standard kanji spelling for the blue demon or ogre.
Kana spelling is sometimes used in children's books or when the kanji is considered difficult.
Compound of 青 (あお, 'blue') and 鬼 (おに, 'demon, ogre'). The exact origin of the blue oni in folklore is uncertain, but the pairing of red and blue oni is a common motif.