The world of fantasy and horror lurks in the shadows of the demon city, whether in the future or in the past. Strange incidents have been occurring in the city, baffling scientists. To uncover the truth, three exceptional girl detectives have united their unique abilities. Kotono, an orphan residing in a convent. Natsuki, Kotono's classmate and a beloved pop idol. Misaki, a mysterious girl battling the nightmares of her past life. While Kotono encounters a boy suffering from memory loss, the story's wheels slowly begin to turn. As they solve the mysteries, the trio confronts a fateful decision that will either save or end humanity at the hands of those seeking Judgement Day. Who shall stand for justice, and who bears the mark of evil?