The tale commences with the introduction of the Hundred, a unique weapon capable of combating the enigmatic Savage life forms inflicting damage upon Earth. In order to attain the status of a Slayer - an expert in military combat employing the Hundred - our protagonist, Hayato Kisaragi, successfully secures admission into the prestigious marine academy city ship, Little Garden. However, his joyous moment is short-lived as he encounters Emil Crossford, who seems to have some inexplicable connection to him. To add to his discomfort, he finds himself challenged to a duel by the school's "Queen," Claire Harvey, who happens to be the most skilled Slayer in the institution.