Mysterious invaders have attacked the Earth! As the Irousu roam the conquered lands, mankind has been driven back, but there’s one last weapon that may still turn the tide: super-powered schoolgirls! At schools like the Shinjugamine Girls Academy, elite classes of Star Guardians alternate between regular schoolwork and learning to kick Irousu behind. It’s a duty that the members of the Shinjugamine Hoshimori force, like freshman Miki Hoshitsuki, take seriously, but as they’re basically normal girls who just happen to get their powers from a magic tree, there are normal life issues they have to contend with as well. With the arrival of their latest mysterious recruit, however, things are about to get deadly serious. Their final exam is about to begin and if they fail, the whole world is doomed in BATTLE GIRL HIGH SCHOOL!