Michio Mita, a sophomore in middle school, discovered that his neighbor, Bachelor Yukiko Kimi, was missing. The police investigation yielded no results and the case reached a deadlock. Subsequently, strange phenomena appeared one after another, such as the mysterious old tramp, the ghost of Yukiko, the disappearance of Teacher Kawakita, etc. Detective Haeya Roku intervened in the investigation. He brought "ghost bait", which caused the appearance of the ghost of Academician Yukiko Kimi and also caused the disappearance of the big treasury. Ghosts frequently haunt him, and Doc is also involved. Yukiko told Doc about the secrets of the fourth-dimensional world, hoping to return to the original world with Doc's help. Will they succeed? How will the mystery of the fourth-dimensional world be revealed?
