Makoto Tagusari, a determined detective, and his younger brother Minoru, a forensic medical examiner, are bound by a tragic past—the brutal murder of their parents years earlier; as the statute of limitations on the case expires just days before its abolition, the brothers are left without justice, pushing them to pursue the truth on their own while working within the system, as the first episode sets the stage for their quest to uncover the culprit behind the long-unsolved family murder.