, also known as , , or , is a disembodied spirit or ghost in Japanese popular belief and fiction that leaves the body of a living person and subsequently haunts other people or places, sometimes across great distances. The term(s) are used in contrast to , which refers to the spirit of those who are already deceased.
Summary
The popular belief that the human spirit (or soul) can escape from the body has been around since early times, with eyewitness accounts and experiences (hauntings, possessions, out-of-body experience) reported in anecdotal and fictional writings. of the living are said to inflict upon the subject or subjects of their vengeance by means of transforming into their form. It is believed that if a sufficient grudge is held, all or part of the perpetrator's soul leaves the body, appearing in front of the victim to harm or curse them, a concept not so dissimilar from the evil eye. The has even made its way into Buddhist scriptures, where they are described as "living spirits" who, if angered, might bring about curses, even just before their death. Possession is another means by which the Ikiryō are commonly believed to be capable of inflicting harm, the possessed person thought to be unaware of this process. However, according to mythology, the does not necessarily act out of spite or vengefulness, and stories are told of the who bears no grudge, or poses no real threat. In recorded examples, the spirit sometimes takes possession of another person's body for motives other than vengeance, such as love and infatuation (for example the Matsutōya ghost below). A person's may also leave the body (often very shortly before death) to manifest its presence around loved ones, friends and/or acquaintances.
Classical literature
In classical literature, The Tale of Genji (ca. 1000) describes the "well known" episode of the (the more archaic term for ) that emerged from Genji's lover Lady Rokujo, and tormented Genji's pregnant wife Aoi no Ue, resulting in her death after childbirth. This spirit is also portrayed in , the Noh play adaptation of the same story. After her death, Lady Rokujo became an and went on to torment those who would later become Genji's consorts, Murasaki and .
In the Heian period, a human soul leaving a body and drifting away is described by the old verb meaning "departure". In The Tale of Genji, the mentally troubled Kashiwagi fears that his soul may be found wandering (), and requests that last rites are performed on his body to stop his soul from escaping if this should happen.
contains the tale "How the Spirit of Omi Province Came and Killed a Man of the Capital". In the tale, a commoner encounters a noblewoman and guides her to the house of a certain in the capital. Little did the guide know that he was guiding the of a woman to her neglecting husband. Upon reaching the house the lady vanishes, though the gates remain shut. Wailing noises are heard inside the house. The following morning, the guide learns that the master of the house had complained the of his former wife was present and causing him illness, shortly after which he died. The guide later seeks out the lady's house in Ōmi Province. There a woman speaks to him through blinds, acknowledging the man's services that day, and showers him with gifts of silk cloth.
The can also possess the object of its infatuation, who is neither rival nor enemy. The , a tale allegedly based on events that occurred during Kyōhō 14 or 15 (1729–1730), a Kyoto merchant named had a teenaged son named Matsunosuke possessed by the spirit of two women who loved him, and who tormented the boy's conscience. On occasion, he would be suspended in mid-air, engaging in conversation as if the girls were present before his eyes, the 's words being spoken through the boy's lips. Finally the family sought help from a renowned priest named Zōkai. The priest successfully exorcised the boy and cured his condition, but rumors had already spread regarding the incident.