According to Japanese belief, some demons are the root of all disasters, both natural and man-made. Japanese demons are not altogether evil but are also tricksters and enjoy playing practical jokes. In the Edo period they began to depict the demons with humour, especially in Netsuke figures 3 . The fear of pain causes the demons to run away. In folklore there are also tales of supernatural creatures called the 'Oni'.
Artists depict the 'Oni' with horns and wearing tiger skins.
These artistic renditions of demons not only represent the supernatural, but also embodiments of the evil facets of human nature. There are invisible demons among the 'Oni' whose presence can be detected because they sing or whistle. The 'Oni' who are women are those transformed into demons after death by jealousy or violent grief. The Buddhist 'Oni' demons did not always represent the forces of evil. In Buddhist lore there are tales of monks who after death became 'Oni' in order to protect temples from potential disasters.