A newly dead person discovers that he's become a ghost. He was murdered, and now as a ghost he wanders around the town. He doesn't want revenge. He just goes to see the person who murdered him simply to ask why.
The ghost not only doesn't hate his murderer, he tries to help. Helping this person can be a challenge, though...
"I never did anything wrong in my life. That's why I was so upset when Schuster murdered me."
- the good ghost