K-9: Keishichou Kouanbu Kouan Dai-9-Ka Inou Taisaku GakariK-9 - Keishichou Kouanbu Kouan Dai-9 Ka Inou Taisaku-gakari; Ｋ－９　警視庁公安部公安第９課異能対策係; K-9: Public Security Bureau, Division 9 – Special Abilities Countermeasure; K-9 – Unidade Especial Contra Habilidades Sobrenaturais; K-9 – Divisão de Contramedidas a Habilidades Sobrenaturais da 9ª Seção de Segurança Pública do Departamento de Polícia Metropolitana

The ability to manifest by committing sins, commonly known as Sin. Amidst the rampant heinous crimes caused by Sin, Ren Hizuki, a detective in the First Investigative Division of the Metropolitan Police Department, was living a life of fierce battles day and night. One day, Ren is ordered to transfer to the newly established special ability crime investigation unit, Public Safety Section 9. There, she meets a cowardly detective named Yujiro Oboro. As she heads to investigate ability-related cases with Oboro, the secrets of Section 9 and the true identity of Oboro begin to come to light.