Joining the Tokyo Metropolitan Police Criminal Investigation Unit, Sakon Futatsuki partners with his brother Ukon to solve a range of cases while staying true to his ideals. In the same division, detective Risa Aioi employs unorthodox methods, becoming infatuated with criminals she pursues and persistently tracking them down. Sakon is troubled by Aioi's controversial tactics, despite their effectiveness. As he delves into her history, he hesitates to challenge her. Meanwhile, Aioi grapples with curbing her obsessions, especially to apprehend a particular fugitive. Fearful for Aioi's well-being, Sakon must confront the notion of fighting fire with fire to prevent disaster.