Set in a 20th-century devastated by an unprecedented global disaster known as Invertia, humanity faces near extinction. Cities are destroyed, but from the cataclysm emerges a new human race called the Genestella, possessing superhuman physical abilities. Corporations known as the Integrated Enterprise Foundations rise to global power, establishing academies to harness these youth. The central stage is Asterisk, a
floating city officially named Seidoukan Academy, famous for hosting the Festa—an international combat tournament where six academies battle for supremacy, granting the winner any single wish.Ayato Amagiri transfers to Seidoukan Academy, outwardly appearing like an ordinary student. However, his hidden motivations are deeply personal: he is searching for his older sister, Haruka, who mysteriously vanished years ago while attending the same school. Upon arrival, Ayato inadvertently walks in on Julis-Alexia von Riessfeld, a proud princess of the small European nation of Lieseltania and Seidoukan’s top-ranked student, half-dressed. This awkward encounter sparks an immediate rivalry that quickly transforms into an alliance when an assassin attacks them. Ayato discovers his own dormant, catastrophic powers, which are sealed by a special weapon called the Ser-Veresta, a magnificent Ogre Lux—a rare, sentient weapon requiring immense mana to wield.To investigate his sister's disappearance, Ayato allies with Julis, joining forces to compete in the upcoming Phoenix Festa, a two-person tag-team tournament. Along the way, they recruit quirky yet brilliant allies, including Saya Sasamiya, Ayato's childhood friend seeking a powerful Lux to protect him, and Kirin Toudou, the reigning
student council president and Seidoukan's number-one swordfighter. As they train, they uncover sinister conspiracies orchestrated by the Integrated Enterprise Foundations, who are ruthlessly experimenting on Genestella students to create ultimate living weapons.The dramatic tension peaks during the Phoenix Festa, where Ayato and Julis face ruthless opponents utilizing forbidden, life-threatening technologies. During the grueling matches, Ayato’s seal begins to fail, threatening to consume him with his own immense destructive power. Through sheer willpower, tactical brilliance, and deepening romantic feelings for Julis, Ayato pushes past his physical limits. They ultimately triumph in the tournament, winning the Phoenix Festa championship. Despite this monumental victory, Ayato’s ultimate quest remains unresolved. Armed with the wish granted by their victory, Ayato and Julis prepare for even greater dangers, knowing that the truth behind Haruka's disappearance is tangled in a much darker, global conspiracy orchestrated by the Academy's shadowy masters.