Dear All!
I find it interesting to see under which circumstances people are said to become "ghosts" in Japan.
For example, in the castle of Himeji, Okiku's Well is known for its famous ghost story called "Banshu Sara-Yashiki." Okiku was once a servant at Himeji Castle. She found out that one of the retainers planned to kill the lord of the castle. She foiled this murder attempt and saved the lord. In revenge, the retainer stole one of the lord's ten treasure dishes. Okiku was tortured to death for the missing dish, and the retainer threw her body into the well. It is said that her voice is still to be heard at night, mournfully counting the remaining crockery.
In other words, Okiku was loyal to her lord, saved him from being murdered, and when the foiled murderer took revenge on her, the lord, instead of rewarding her for her loyalty and saving her in exchange, let her be tortured to death: this represents a profound betrayal of loyalty, and utter humiliation. This, clearly, is regarded, by Japanese folktales, as a reason for not finding peace after death.
Warmly!
Evelin