The detective agency received two commissions in succession. The first commission was from a young woman who asked to investigate her husband's extramarital affair. The second commission was from an old man who wanted to find a boy who disappeared after running away from home 20 years ago. During the investigation, the male protagonist Akagawa discovered that all the targets were focused on a young professor named Nagashima Ryuya. However, during the subsequent investigation, he found that he had fallen into some kind of strange cycle...