There was once a mailbox that was created for children who were suffering from the adults. If you mail your letter, the "Devil of Neverland" would punish the bad adults. However, the "devil" suddenly disappeared after an incident and ten years have passed since then. In current time, Rikiya Soejima is a former postman working at a hospice and receives a mysterious letter that writes, "The Devil of Neverland" is not over. Rikiya later went back to work at the post office and around the same time, a piece of paper was found in the mouth of a strangled body left abandoned on a riverside. The paper writes, "The Devil of Neverland Returns".