Kirukiru Amō transfers to Private Aichi Symbiosis Academy after expulsion from her previous school, forced out due to a massive brawl where she fought Nomura Fudou and inflicted severe injuries that hospitalized him. At Aichi Academy, she swiftly earns the title "Empress" by single-handedly defeating two members of the Supreme Five Swords, Rin Onigawara and Mary Kikakujō, cementing her dominance through fear and combat prowess.

She possesses exceptional combat abilities, specializing in self-taught Uechi-Ryu Karate adapted for lethal effectiveness. Her signature techniques include the "Auto-counter," using hardened fingers to preemptively slash or stab opponents, and "Tegatana," enabling her to pierce concrete or flesh with precision. Rigorous conditioning grants her skin durability comparable to steel and concrete-like density for internal fluids, though blunt-force attacks remain a weakness. She demonstrates wall-level destructive capacity and subsonic speed, surpassing most peers except Nomura.

Initially cold and intimidating, her personality shifts drastically after losing a rematch to Nomura at Aichi Academy, developing an all-consuming romantic obsession with him. She refuses to accept his rejection, reacting with intense jealousy towards his interactions with other female students, especially Supreme Five Swords members. This obsession fuels manipulative schemes to isolate him. Her backstory reveals a violent past as a gang leader, marked by disregard for rules and authority. Though primarily self-interested, she displays occasional loyalty, such as confronting Satori Tamaba for attempting to blackmail Nomura.

Following escalating conflicts involving the Supreme Five Swords and Nomura, she is expelled from Aichi Academy and forcibly transferred to Private Hokkai Symbiosis Academy, concluding her primary arc.