Much in the future, the lifeforms called Gadoll abruptly arose as a danger to humankind. The last surviving people on Earth restrict themselves into the Tank, a decrease district at the giant cellular fortress Deca-Dence. While the Gears who reside on the top floors are those that head out to fight within their Electricity, many Tankers are content to give support in the backlines, butchering Gadoll meat along with strengthening defenses. Natsume is one of those who’d rather visit the front lines; undeterred with her prosthetic right armshe attempts to join the few of Tanker soldiers that combine the Gears in battle.But despite her peers in the orphanage each getting their work duties, Natsume’s enlistment into the Electricity remains unapproved. Meanwhile, she starts a job as a cleaner in an armor fix team headed from the hard-nosed and apathetic Kaburagi, who appears to be greater than he lets on. Though originally cold to his idealistic weak, he soon admits in her the capacity to upset the status quo of earth.