The film opens with a scene where there are mass protest in front of cops in riot gear. As this riot is happening, the focus goes towards a girl in redcoat, navigating through the rioting crowd to deliver a satchel charge working for an anti-government rebel faction known as the Sect. After delivering the initial satchel charge, she navigates through the sewers to get the next satchel charge from the heavily armed Sect members.
While in the sewers, that heavily armed Sect members confront the Panzer Cops in an one-sided armed battle favoring the Panzer Cops. Upon hearing the gunfires, the girl in the redcoat tries to escape out of the sewers. While catching her breath, a single Panzer Cop sneaks up on her to her surprise. She decides to trigger the satchel charge she was carrying to the Panzer Cop's puzzlement and hesitation, and kills herself. The entire city blocks electric grid goes down, which causes the riot above ground to go out of control. The lone Panzer Cop who faced the girl removes the Panzer armor to reveal the main protagonist's face, Kazuki Fuse.
The bombing that resulted in the blackout and massive riot caused an inquiry into the Fuse's organization, Kerberos. Fuse is blamed for the incident for hesitating to shoot the girl with the satchel charge, and is sent back for retraining. While visiting the grave of the dead girl, Fuse meets Kei Amemiya, who states that she is the dead girl's older sister and is also wearing a red jacket. They start to develop a relationship with each other and becomes very close to each other. At the same time, a rival government organization to Kerberos, Public Security, intends to discredit Kerberos, by taking advantage of Fuse's demotion and incident. It is then revealed that Kei is a Public Security agent working to discredit Kerberos using Fuse.
Public Security plots a scheme and a trap to get Fuse caught in a satchel charge exchange with Kei. Fuse is able to see through the trap and takes Kei away from the trap setup by Public Security. Public Security chases them down, but they made an escape. Fuse and Kei share a thought of running away together from the participation in the political plot, but Fuse refuses begrudgingly.
Fuse and Kei goes back into the sewers, where it is found out a secret sub-organization of Kerberos was waiting for them, and it is a trap to lure out Public Security by falling into their own trap on purpose to begin with. It is also discovered that Fuse is working for this sub-organization. Fuse gears up in the Panzer Cop gear and greets the Public Security agents who thought they were the ones who were chasing down Fuse. Fuse kills all the agents that chased them.
Fuse and his group decides to kill Kei thinking it was better for Public Security to be never able to confirm whether Kei is alive or not. After much hesitation, Fuse reluctantly kills Kei.