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.