In September 1944, in the city of Sasebo in Fuso, a young witch-in-training named Hikari Karibuchi reunites with her sister Takami, who is part of the Third Aerial Squadron. Discovering that Takami is to be dispatched to Petersburg, Orussia, to join the 502nd Joint Fighter Wing, also known as the Brave Witches, Hikari decides to participate in a selection exam to be dispatched to Petersburg as well to join her sister, competing against fellow classmate Mia Misumi in a mock battle race...