People have heard of out-of-body experiences, but the Japanese belief takes it a step further. According to folklore, a living spirit is what happens when a spirit leaves a living person to haunt someone, like an out-of-body experience. Supposedly, it takes a strong emotion to provoke this happening – usually hate. If a person holds a strong grudge against another, their spirit could leave their bodies to cause harm against that person, even possibly possessing it.
Myths and folklore are littered with ‘villains’ in the form of an old woman. Think Baba Yaga, and virtually every old witch in the fairytales. In Japan, there is the infamous onibaba (鬼婆) from which noh plays and films have draw inspiration.