The protagonist, Akugyou Souma, is a private detective operating in a world where the line between reality and the surreal is blurred. Souma is known for his eccentric behavior and unorthodox methods of investigation. He is often called upon to solve cases that defy conventional logic and involve supernatural or unexplained elements.

The main plot of the game unfolds when Souma is hired to investigate a series of bizarre incidents that occur in a seemingly quiet town. As he delves deeper into the cases, Souma uncovers a complex plot involving conspiracies, dark secrets, and forces beyond human comprehension. The cases touch on themes such as corruption, revenge, and the conflict between good and evil, often challenging traditional notions of morality.

Each "jiken file" (case file) that Souma investigates brings new revelations and intriguing characters, from figures of the criminal underworld to supernatural entities. The story is rich in twists and turns, and the decisions the player makes during the investigations can influence the outcome of each case.