Sayaka Kitaoji presides over the Debutante Club at St. Ignacio’s School for Girls, where membership is fiercely sought for its perceived sway over future influence. As heir to the Makuhari Heavy Industries dynasty, her family’s financial dominance over the school grants her unchecked power, which she wields to fuel her vision of a Japan reshaped under matriarchal rule, leveraging her lineage’s industrial and technological might.

Her vendetta against Reika Ayanokoji, head of the Etiquette Club, spans both school corridors and corporate boardrooms, pitting Makuhari against the Uruyasu conglomerate helmed by Reika’s family. Bound by blood yet divided by ideology, Sayaka scorns her relative’s pacifism, clashing violently as the Etiquette Club’s covert mecha task force—armed with Uruyasu’s cutting-edge technology—becomes a prize she ruthlessly pursues.

A master of spectacle, she flaunts her supremacy through acts like descending to campus aboard a private spaceship trailed by a crimson carpet. Her loyal yet tormented subordinate, Todou, endures her manipulation and scorn while executing schemes to cripple the Etiquette Club, from bank heists to deploying Makuhari’s own mechanized units.

Her unchecked aggression halts only when her mother, Makuhari’s CEO, intervenes following a botched plot to annihilate the rival club using a commandeered military fortress. Forced to endure the Etiquette Club’s reinstatement as a humbling lesson, Sayaka adapts, channeling her ambitions into sanctioned rivalry while plotting to outmaneuver Reika within these new constraints.

A fusion of aristocratic audacity and calculated ambition, she intertwines scholastic politics with corporate warfare, convinced of her destined supremacy. Even as familial reins tighten, her resolve to overturn Japan’s power structures remains unshaken, cementing her role as a relentless adversary sculpted equally by her ambitions and the limits they defy.