I still don't know where the nursery rhymes started and when they ended. Will those innocent, cute and interesting sounds seduce you? Let's wait and see. The general rule of this world is to destroy any "dangerous" ghost. People must have great trust in the general rule. The person who manages the general rule is a human being. Members enter the world through teleportation. They need to find a special pen (hidden in the body of a non-player) and write it to the place where the nursery rhymes are spread. (You must not hurt others or use the hands of ghosts to hurt others.)
Intention: Nursery rhymes are reminders and destruction.