Before he became an Enforcer for the Public Safety Bureau, Teppei Sugo was a decorated drone pilot called First Guardian, flying eye-in-the-sky support for a marine ground squad led by Itsuki Otomo. This film goes back to the Okinawa deployment that broke him, following Sugo through the operation that cost him his comrades and left him a latent criminal. It is the second feature in the Sinners of the System trilogy of Psycho-Pass spin-offs.