Akebono Mayu, an ordinary police sergeant in the Teito Police Department, holds a secret identity as a special inspector assigned to the covert investigative unit known as Zero Division. She is the only agent capable of wielding the unique "Geometric Camouflage," a special suit allowing her to perfectly blend into any environment—an essential tool in her mission to eliminate the criminal organization known as Beluga. However, her sole superior, Yukihiro Mizusawa, is assassinated by Beluga forces. Mayu herself is captured and pushed to the brink as she endures brutal torture and sexual assault at the hands of Seisho Kawai and his subordinate Konuma. Barely escaping, she reloads her weapon only to come face-to-face once more with Seisho Kawai. Their final confrontation is charged with a complex mix of past bonds and bitter rivalry, determining the ultimate course of her fate.