taken from asianart.com
If the soul of the dead is not purified, it can return to the land of the living in the guise of a ghost. Also, if a dead person is not delivered, through prayer, from personal emotions such as jealousy, envy or anger, the spirit can return in a ghostly guise. The ghost haunts the place where it lived and persecutes those responsible for his or her bitter fate. The ghost will remain until released from its suffering through the good offices of a living person who prays that the soul of the dead may ascend.
During the Heian era (794-1185) it was believed that ghostly spirits floated above the living causing disease, plague and hunger. In the Kamakura era (1185-1333) a belief was reinforced that spirits turned into small animals, such as raccoons and foxes, that led people astray. Household objects, when a hundred years old, could become deities in the Muromachi period (1336-1573). These venerable objects were thought to possess special powers and were treated with care and respect. And in the Momoyama (1573-1600) and the Edo periods (1603-1868) there was a belief that if a man died of disease or in an epidemic, he turned into a monstrous demon.
The despotic feudal regime which prevailed during the Edo period, combined with natural disasters that occurred at that time, added to the lore of evil and vengeful spirits and ghosts. At the close of the Edo era, edicts were passed forbidding the display of theatrical performances with the theme of frightening ghostly spirits, for fear of undermining the government.
Most creatures in stories of unfortunate spirits were women. They were vengeful ghosts, and the greater the misery endured by the woman during her lifetime, the more threatening her ghostly spirits would be after her death. Cruelty to women is a recurring theme in Japanese lore and legend.
Ghost stories were dramatized for puppet theaters in the early 1700’s. Ghost stories then began to be enacted in various theaters including Sumizu theater of Osaka and Nakamura-za theater in Edo.
Vengeful spirits became the central theme in the Kabuki theater at the end of the 18th century. Murder was presented on the stage in all its gory details, and female ghosts were distinctly portrayed. The scenes of crime and bloodshed presented were shocking and intended to arouse suspense and fear. Surprisingly, these plays were quite popular, and print artists reproduced many scenes of these Kabuki productions. An example of this theme is in one of the plays enacted at the Kabuki theater called the ‘The Rock That Weeps at Night.”
“At Tokaido, on the road between Tokyo and Kyoto, there is a famous rock known as ‘The Rocks that Weeps at Night’. Lore tells of a pregnant woman travelling along this road at night to meet her husband. Bandits accosted her and she was barbarously murdered. Her blood spilled onto the rock, which became the habitation of her ghost. Legend has it that the rock weeps at night."
Relevance to Urusei Yatsura
Ghost stories are a big part of Japan's storied culture. Since UY is built upon lampooning Japanese culture, you can bet ghosts come up a lot in UY. Many ghost characters are based upon actual events (although don't ask me to point any out). Some examples of ghost characters: Kotatsu-neko, Nagisa and her father, The seaside resort ghost, Sakura's evil spirits, Ten's ghost child friend, The ghost girl in winter clothing who wanted to date Ataru, Old Man Willow, the list goes on.