oni, in Japanese folklore, a type of demonic creature often of giant size, great strength, and fearful appearance. They are generally considered to be foreign in origin, perhaps introduced into Japan from China along with Buddhism.

What oni means?

They too were evil spirits that were invisible to the eye. It is said that the word Oni itself is derived from the On'Yomi reading, logographic Chinese characters that are also used in the Japanese writing system, meaning to conceal or hide. This being the case, Oni ultimately means an invisible spirit, or being.

Is the oni evil?

Oni are mostly known for their fierce and evil nature manifested in their propen- sity for murder and cannibalism. Notwithstanding their evil reputation, oni possess intriguingly complex aspects that cannot be brushed away simply as evil.