In August 2015, amid a rise in heinous social crimes, a new countermeasure unit called the "Ladies' Special Task Force for Severe Sexual Crimes" was established. This is the story of Arisa, a dedicated female investigator who voluntarily left her position as a teacher and stepped into the depths of evil of her own free will. After enduring rigorous training, she prepares to confront criminal operations head-on, marking the beginning of a new battle.