One day, Minon's beloved brother suddenly disappeared. All he left behind was the information that he had been taken hostage by "A," a murderer who is causing quite a stir, and information about a mysterious town called "Shadow Fog Town," which he had sent to someone in an e-mail. In order to get to the place, which does not appear in any searches, a high school girl, Minon, tries to sneak into a suspicious building where she last saw her brother. However, it turns out to be the entrance to a forbidden place that must never be entered. An underground search drama depicting a nest of "great evil" where no common sense can be understood!