A soldier trained to kill since childhood gets dropped into high school to protect a girl, and the show's genius is that both halves are equally serious. Sousuke treats a school festival like a military operation because that's literally all he knows, and watching him fail at normal life hits harder than it has any right to. The mecha fights are real, the stakes are real, but so is the loneliness of a kid who doesn't know how to be seventeen.

Sousuke Sagara is a seasoned military operative for the covert organization MITHRIL, raised on the battlefield rather than in ordinary society. His new assignment places him undercover as a classmate of Kaname Chidori, a teenage girl considered a "Whispered" whose unconscious scientific knowledge makes her a target for intelligence agencies and other groups. Two teammates, Kurz Weber and their commanding officer Melissa Mao, back him up from a distance. The problem is that Sousuke has little idea how civilian life works, and his poor social skills draw unwanted attention while his odd conduct makes Kaname suspicious of him. Between guarding her from real threats, facing enemies from his past, and learning to live as an average student, Sousuke finds the everyday side of the mission as hard as any fight. Full Metal Panic mixes sci-fi mecha action with comedy about a soldier out of his element.