Rebirth of the Lord of the Back Room

On a graduation trip, a bus carrying seven prospective college students drove into the manor, and five of them died one after another within three years. One of the survivors became a detective to investigate the matter and died suddenly during the investigation. After being reborn, he returned to the road to the manor. He gradually got closer to the truth, but found that the world was not simple. The manor had the entrance to the back room, and the moment the student stepped into the manor, part of him had stayed there forever.