Hikari Senami, a bespectacled middle school student at the Eastern Defense Academy, navigates the demands of this private institution founded under Japan’s National Defense Education Law. Enrolled in its rigorous military training program, she faces catastrophe during a routine August 2026 field exercise at the Fuji Training Facility when mercenaries ambush her class, intent on seizing the experimental Regeneratable Artificial Nerve.

Forced into a desperate retreat with classmates like Kazuki Kurobe, Hikari clutches the stolen technology fueling the conflict. Tense interactions amid their flight expose her vulnerability—voicing doubts about their odds or confessing fears mid-combat—underscoring her dependence on comrades for both morale and tactical guidance.

Her resolve fractures during a final skirmish: after exhaustive efforts to safeguard the prototype and outmaneuver superior forces, she is cut down by enemy fire while scrambling for cover. This loss marks a turning point in the escalating crisis, intensifying the survivors’ battle to salvage their reputations and fulfill their objective against mounting threats.