A candidate commanding officer from the Fuso Empire is on her way to join the 501st Joint Fighter Wing — the Strike Witches — for a training exercise. Takei Junko's introduction to the unit happens while the military is issuing a broader operational order: a coordinated strike against Neuroi forces massing at the Gallian coastline, with the goal of establishing a new frontline base at a tactically critical position. Her arrival and the operation arrive at the same time.