At Seishou Academy, every girl is literally based on some version of a nation's military firearm. For newly recruited human instructor Genkoku, it's going to be difficult to adjust to teaching a living arsenal of high-caliber cute girls with tricky names like FNC (Funko), M16A4 (Ichiroku), L85A1 (Eru), and SG550 (Shigu). He tries to avoid any misunderstandings with them, but if the inevitable occurs with Funko when she fires on him in retaliation.