The Asterisk War unfolds in the aftermath of the Invertia, an unprecedented disaster that reshaped the previous century, weakened the world's existing nations, and allowed the Integrated Empire Foundation to rise to power. The catastrophe also gave birth to a new species of humans known as the Genestella, people born with extraordinary physical abilities. Their elite are selected from around the world to attend six top schools, where they duel in public entertainment battles called Festas.
At Seidoukan Academy, a prestigious school that has been struggling with declining performances, scholarship transfer student Ayato Amagiri arrives with a purpose that has nothing to do with glory. Through a series of events, he accidentally sees the popular Witch of Resplendent Flames, Julis-Alexia von Riessfeld, half-dressed, and an enraged Julis immediately challenges him to a duel for intruding on her privacy. The duel is later voided by the student council president, but Ayato makes it clear that he has no interest in Festas themselves. Instead, he has enrolled in the academy to investigate the whereabouts of his missing elder sister.
As Ayato becomes surrounded by some of the most talented Genestella on the planet, a more devious plot begins to surface within the academy's competitive world. Caught between rivalries, hidden agendas, and the pressure to prove himself, he is forced to pursue victory on his own terms while navigating a school system where every match can shift the balance of power.