Deca-Dence

Long ago, humanity nearly went extinct after the sudden appearance of monstrous creatures called Gadoll. The survivors now live in a massive mobile fortress called Deca-dence, towering 3000 meters high to shield them from the Gadoll. Inside Deca-dence, people are divided into two groups: the Gears, warriors who battle the Gadoll, and the Tankers, who lack the ability to fight. Natsume, a Tanker girl, dreams of becoming a Gear despite the odds. One day, she crosses paths with Kaburagi, a jaded armor repairman. Though they seem like opposites-Natsume with her unwavering optimism and Kaburagi with his resigned realism-their meeting sets in motion events that will alter the fate of their world.