This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (November 2011) (Learn how and when to remove this template message)
Y?rei () are figures in Japanese folklore analogous to Western notion of ghosts. The name consists of two kanji, ? (y?), meaning "faint" or "dim" and ? (rei), meaning "soul" or "spirit". Alternative names include (B?rei), meaning ruined or departed spirit, (Shiry?) meaning dead spirit, or the more encompassing (Y?kai) or (Obake).
According to traditional Japanese beliefs, all humans have a spirit or soul called a (reikon). When a person dies, the reikon leaves the body and enters a form of purgatory, where it waits for the proper funeral and post-funeral rites to be performed so that it may join its ancestors. If this is done correctly, the reikon is believed to be a protector of the living family and to return yearly in August during the Obon Festival to receive thanks.
However, if the person dies in a sudden or violent manner such as murder or suicide, if the proper rites have not been performed, or if they are influenced by powerful emotions such as a desire for revenge, love, jealousy, hatred or sorrow, the reikon is thought to transform into a y?rei, which can then bridge the gap back to the physical world. The emotion or thought need not be particularly strong or driving, and even innocuous thoughts can cause a death to become disturbed. Once a thought enters the mind of a dying person, their y?rei will come back to complete the action last thought of before returning to the cycle of reincarnation.
The y?rei then exists on Earth until it can be laid to rest, either by performing the missing rituals, or resolving the emotional conflict that still ties it to the physical plane. If the rituals are not completed or the conflict left unresolved, the y?rei will persist in its haunting.
Oftentimes the lower the social rank of the person who died violently or who was treated harshly during life, the more powerful as a y?rei they would return. This is illustrated in the fate of Oiwa in the story Yotsuya Kaidan, or the servant Okiku in Banch? Sarayashiki.
In the late 17th century, a game called Hyakumonogatari Kaidankai became popular, and kaidan increasingly became a subject for theater, literature and other arts.Ukiyo-e artist Maruyama ?kyo created the first known example of the now-traditional y?rei, in his painting The Ghost of Oyuki. The Zensh?-an in Tokyo houses the largest single collection of y?rei paintings which are only shown in August, the traditional month of the spirits.
Today, the appearance of y?rei is somewhat uniform, instantly signalling the ghostly nature of the figure, and assuring that it is culturally authentic.
While all Japanese ghosts are called y?rei, within that category there are several specific types of phantom, classified mainly by the manner they died or their reason for returning to Earth:
There are two types of ghosts specific to Buddhism, both being examples of unfulfilled earthly hungers being carried on after death. They are different from other classifications of y?rei due to their religious nature:
In Japanese folklore, not only the dead are able to manifest their reikon for a haunting. Living creatures possessed by extraordinary jealousy or rage can release their spirit as an ikiry? (), a living ghost that can enact its will while still alive.
The most famous example of an ikiryo is Rokuj? no Miyasundokoro, from the novel The Tale of Genji. A mistress of the titular Genji who falls deeply in love with him, the lady Rokuj? is an ambitious woman whose ambition is denied upon the death of her husband. The jealousy she repressed over Genji transformed her slowly into a demon, and then took shape as an ikiry? upon discovering that Genji's wife was pregnant. This ikiry? possessed Genji's wife, ultimately leading to her demise. Upon realising that her jealousy had caused this misfortune, she locked herself away and became a nun until her death, after which time her spirit continued to haunt Genji until her daughter performed the correct spiritual rites.
Y?rei often fall under the general umbrella term of obake, derived from the verb bakeru, meaning "to change"; thus obake are preternatural beings who have undergone some sort of change, from the natural realm to the supernatural.
However, y?rei differ from traditional bakemono due to their temporal specificity. The y?rei is one of the only creatures in Japanese mythology to have a preferred haunting time (midtime of the hours of the Ox; around 2:00am-2:30am), when the veils between the world of the dead and the world of the living are at their thinnest). By comparison, normal obake could strike at any time, often darkening or changing their surroundings should they feel the need. Similarly, y?rei are more bound to specific locations of haunting than the average bakemono, which are free to haunt any place without being bound to it.
Yanagita Kunio generally distinguishes y?rei from obake by noting that y?rei tend to have a specific purpose for their haunting, such as vengeance or completing unfinished business. While for many y?rei this business is concluded, some y?rei, such as Okiku, remain earthbound due to the fact that their business is not possible to complete. In the case of Okiku, this business is counting plates hoping to find a full set, but the last plate is invariably missing or broken according to the different retellings of the story. This means that her spirit can never find peace, and thus will remain a jibakurei.
Some famous locations that are said to be haunted by y?rei are the well of Himeji Castle, haunted by the ghost of Okiku, and Aokigahara, the forest at the bottom of Mt. Fuji, which is a popular location for suicide. A particularly powerful onry?, known as Oiwa, is said to be able to bring vengeance on any actress portraying her part in a theater or film adaptation.
Okiku, Oiwa, and the lovesick Otsuya together make up the San O-Y?rei (Japanese: ?, "three great Y?rei") of Japanese culture. These are y?rei whose stories have been passed down and retold throughout the centuries, and whose characteristics along with their circumstances and fates have formed a large part of Japanese art and society.
The easiest way to exorcise a y?rei is to help it fulfill its purpose. When the reason for the strong emotion binding the spirit to Earth is gone, the y?rei is satisfied and can move on. Traditionally, this is accomplished by family members enacting revenge upon the y?reis slayer, or when the ghost consummates its passion/love with its intended lover, or when its remains are discovered and given a proper burial with all rites performed.
The emotions of the onry? are particularly strong, and they are the least likely to be pacified by these methods.
On occasion, Buddhist priests and mountain ascetics were hired to perform services on those whose unusual or unfortunate deaths could result in their transition into a vengeful ghost, a practice similar to exorcism. Sometimes these ghosts would be deified in order to placate their spirits.
Like many monsters of Japanese folklore, malicious y?rei are repelled by ofuda (), holy Shinto writings containing the name of a kami. The ofuda must generally be placed on the y?reis forehead to banish the spirit, although they can be attached to a house's entry ways to prevent the y?rei from entering.