Sousuke, Kaname, and their friends visit the Narashino military festival during their summer break. At the festival's annual AS competition, Sousuke helps out the Narashino team (an element of the 1st Airborne Brigade), who lose to the Nerima team every year. His classmate, Shinji Kazama, a military otaku, also reconciles with his father, who is the Narashino team's commanding officer.