Eiji Takeuchi

On the surface, Koudo Ikusei Senior High School is a utopia. The students enjoy an unparalleled amount of freedom, and it is ranked highly in Japan. However, the reality is less than ideal. Four classes, A through D, are ranked in order of merit, and only the top classes receive favorable treatment. Kiyotaka Ayanokouji is a student of Class D, where the school dumps its worst. There he meets the unsociable Suzune Horikita, who believes she was placed in Class D by mistake and desires to climb all the way to Class A, and the seemingly amicable class idol Kikyou Kushida, whose aim is to make as many friends as possible. While class membership is permanent, class rankings are not; students in lower ranked classes can rise in rankings if they score better than those in the top ones. Additionally, in Class D, there are no bars on what methods can be used to get ahead. In this cutthroat school, can they prevail against the odds and reach the top? [Written by MAL Rewrite]

Far in the future, the lifeforms known as Gadoll suddenly arose as a threat to humanity. The last surviving humans on Earth confine themselves to the Tank, a lower district in the giant mobile fortress Deca-Dence. While the Gears who live on the upper floors are warriors who go out to fight as part of the Power, most Tankers are content to provide support from the backlines, butchering Gadoll meat and reinforcing defenses. Natsume is among those who would rather go to the front lines; undeterred by her prosthetic right arm, she seeks to join the small number of Tanker soldiers who join the Gears in combat. But despite her peers at the orphanage each receiving their work assignments, Natsume’s enlistment to the Power remains unapproved. In the meantime, she begins a job as a cleaner in an armor repair team led by the hard-nosed and apathetic Kaburagi, who seems to be more than he lets on. Though initially cold to his idealistic subordinate, he soon recognizes in her the potential to upset the status quo of the world. As Natsume’s new mentor, Kaburagi prepares her for the special and unique role as a game-changing bug in the system. [Written by MAL Rewrite]