In a world embroiled in war against the powerful alien race Neuroi, a fresh fighter squadron emerges to combat the threat. The 502nd Joint Fighter Wing, known as the Brave Witches, takes to the eastern front, braving the icy expanse of Orussia in defense against the invaders. When a member of the squadron is injured en route to headquarters, her sister Hikari Karibuchi steps forward to fill her shoes. Lacking extraordinary powers, Hikari is resolute in meeting the squadron's standards and earning her place as a valuable member of the Witches.