Also onryo. Unquiet or vengeful spirits, typically of those who have died violently or unhappily and without appropriate rites. Unless pacified, normally by Buddhist rites but exceptionally by enshrinement as a kami (see for example Sugawara, Michizane) they may haunt or inflict suffering on the living. A belief in goryo or onryo and the necessity to pacify them underlies much traditional and modem Japanese religion and is a favourite theme of the new religions, many of which aim to reinforce ancestor-reverence. The pacification of ancestors is also seen as a form of purification, an expulsion of evil and an expression of filial piety, thus answering to magical, soteriological and moral dimensions of the Japanese religious tradition.
See Goryo-e.
A Popular Dictionary of Shinto. Brian Bocking.