What is an akuryo? You might have heard the term somewhere before. An akuryo, or akurei, (悪霊) is a general term for a spirit that causes harm to the living. In English we might refer to an akuryo simply as an evil spirit. Sicknesses and misfortune are often attributed to them and their curses.
Shinto priests, Buddhist monks, and shamans are often called upon to cleanse akuryo when they are discovered to be haunting a person.
“Akuryo” is a broad, catch-all term that features many types of evil spirits from all sorts of different religions.
How about onryo? This term is even more common, and likely one you’ve seen thrown about in Japanese horror media quite a bit. Onryo (怨霊) are a type of akuryo; spirits that appear when a person was wronged in life. They return to seek vengeance for the suffering they were forced to endure during life and are among the most fearsome of all Japanese spirits.
Some of the most famous onryo include Sugawara no Michizane, Taira no Masakado, and Sutoku Tenno. These three are called the Nihon Sandai Onryo, or Three Great Onryo of Japan. They came to be called this because their influence on books and kabuki plays during the Edo Period was massive. They were the big three terrifying ghosts that audiences loved to hear about.
An onryo does not necessarily have to be the spirit of a dead person. They can occasionally be ikiryo, or living spirits, where a person has become so full of hatred and malice while alive that it causes their spirit to detach itself from their body to seek revenge.
If you think of the ghosts seen in Japanese horror today, you’re probably thinking of an onryo. Sadako and Kayako are two of the most famous modern examples of onryo; spirits that returned from the grave to take our their fury on the people and world who wronged them. They’re typically visualised as having white skin with long black hair, and this comes from their popularity in Kabuki plays during the Edo Period. This type of make-up and styling was used to make an actor easily distinguished as a ghost.