Onryō is a Japanese ghost that is really, really angry. It is said that these ghosts are usually people who have died in a terrible way or have been wronged in some way while they were alive. These ghosts cannot move on to the afterlife because they are too angry and want revenge.
Now, when someone becomes an onryō, they may start haunting people, places or objects that have something to do with their death or their betrayal. They may also try to scare or harm the people who wronged them while they were alive.
Sometimes, onryō can be really scary and dangerous. They may have special powers or abilities, like the ability to fly or to make objects move on their own. They can also appear in different forms, like a mist, a shadow or a human-like figure.
In Japanese culture, onryō are usually associated with horror stories and scary movies. They are a reminder that if you do something wrong to someone, you may end up facing the wrath of their angry spirit. So, always try to do the right thing and be kind to others, even after they are gone.