In the prestigious Psycho-Pass Academy, one club enforces justice across the school's premises: Public Safety Bureau (PSB). The club operates in the name of the Sibyl System—the teachers' watchful eyes—to keep the school safe from vandalism. To this end, they utilize guns called Denominators that measure one's Delinquency Coefficient, the likelihood to turn delinquent.

Akane Tsunemori is a freshman who finds her way into PSB. There, she meets two upperclassmen: Nobuchika Ginoza, who takes his job seriously; and Shinya Kougami, Nobuchika's "dog" and a potential delinquent eradicating wrongdoers. Allying herself with this unconventional Disciplinary Committee, Tsunemori begins her ridiculous high school days as she investigates anything that could disrupt the precious peace.