A murdered person can leave behind "echoes"—traces of their last moments that Minami Asako can pick up on and experience the victim's fate both mentally and physically. Together with his handler, Superintendent Hiroto Kuroiwa, Asako works at the Tokyo Metropolitan Police Department, helping investigate some of the most difficult murder cases by utilizing this unique ability. But its usage is incredibly taxing, as Asako is possessed by the victim's echoes until their killer is brought to justice, finding rare moments of respite only when physically in contact with another person. When Kuroiwa's ex-wife, Mari Agata, is murdered, he feels a sense of personal responsibility to aid with the case and rushes to the scene. Though no suspect is immediately obvious, Asako experiences Mari's lingering feelings for Kuroiwa firsthand. As the case drags on, Asako begins to wonder whether his feelings for his handler are his own or merely echoes of Mari's. [Written by MAL Rewrite]