The Mystery of Ghost Knocking on the Door

There is a rumor in a certain university in a certain city: A girl inexplicably committed suicide by jumping off a building. Since then, many people have seen a shadow similar to the girl floating in the corridor at night. Later, some people were really scared and invited an immortal. The immortal looked at it and said that the ghost of the dead woman was still there. He wanted to go back to get his things, but he couldn't find his dormitory. Three women moved into 601, but the little girl heard a knock on the door late at night. After that, a series of strange events continued to happen... It is said that the dead girl lived next door to them and often went to the wrong door during her lifetime...