Brave Witches: Petersburg Grand Strategy takes place between episode 07 and episode 08 of Brave Witches.
Brave Witches: Petersburg Grand Strategy will receive a limited theatrical release in Japan beginning on May 13, 2017.
A 15 second TV spot is now available online for Brave Witches: Petersburg Grand Strategy, the unaired 13th episode of the 2016 Brave Witches TV anime, which also features guest appearances by characters from the earlier Strike Witches TV anime.