The Onryo is either a male or female spirit which cannot move into the afterlife due to the entity's goal to seek vengeance against the people or person who wronged them. The most common type of Onryo are female humans who were murdered, abandoned, or raped by the most evil of men (the same with males but, mostly uncommon). Being more aggressive and violent then any type of Japanese spirit, they're relentless on seeking revenge on the person who wronged them or anyone who has a mutual relationship with the target (new wife, children, and friends). In appearance, the Onryo wears either the clothing which she/he wore during burial (mainly white burial kimono for Japanese females); wild, unkempt long black hair, and either white or indigo colored faces. The only way to get rid of an Onryo is by either accepting one's fate or exorcisms.
The illustration above is a perfect example of a female Onryo. These types of ghosts can be also linked to natural disasters and are usually seeking for justified vengeance but, this isn't always the case.