Soukou Musume Senki

Riko Morisawa expects an ordinary trip to Tokyo, but buying an LBX model kit ends with her falling through the sky of a different Japan. Before she hits the ground, combat armor based on the model she opened forms around her. She soon learns that this world is being devastated by Mimesis, destructive metallic life-forms that move between worlds and consume everything in their path.

Four girls equipped with similar armor rescue Riko and bring her into their unit. She has no idea how to return home and no real combat experience, yet the search for answers leads through ruined regions where hesitation can be fatal. As the five girls learn to rely on one another, Riko's wish to go home becomes inseparable from their struggle to keep this world alive long enough to find a way back.