Kōyō Ozaki holds prominence as a strategic Port Mafia executive and mentor, her tall, slender frame adorned in a black-and-pink kimono embroidered with crimson spider lilies, a maroon bow, and a gradient-pink mantle. Light scarlet hair is swept into a traditional bun fastened by golden kanzashi, accented with a red ribbon and pink fur clip. Her violet eyes in the manga shift to cherry red in the anime, accompanied by subtle stylistic alterations to her attire. Grace masks a cynical worldview forged by tragedy: a failed escape attempt in her youth with a revered companion ended in his execution, cementing her conviction that those born into darkness perish in the light. She imposes this philosophy on protégé Kyōka Izumi, weaponizing fear to deter defiance. Kōyō manipulated Kyōka by falsely confessing to her parents’ deaths, shackling her to the mafia through guilt. Yet beneath her ruthlessness lies genuine care—after Kyōka’s defection, Kōyō intercepted a government convoy to expose the truth, covertly aiding her. She avoids harming Kyōka or her allies in clashes, though resents figures like Atsushi Nakajima for enabling her departure. Her ability, Golden Demon, summons a lethal sword-wielding specter under her absolute command, distinguishing her mastery from Kyōka’s unstable counterpart. This power cements her role in high-stakes operations, including clashes with the Guild. Initially resistant to Chūya Nakahara’s informal “ane-san” address, she gradually accepted their camaraderie. Her loyalty to the Port Mafia remains pragmatic, laced with lingering disdain for past leadership. Though once obsessively controlling Kyōka, Osamu Dazai’s influence spurred her to relinquish psychological manipulation, permitting the girl’s autonomy—evidenced during the Cannibalism incident, where she refrained from directly attacking her. Inspired by novelist Ozaki Kōyō’s *The Golden Demon*, her persona mirrors themes of moral decay. Personal preferences—kinpura, pickles, and a disdain for abstract ideals like hope—underscore her survivalist pragmatism, rounding a figure entwined in the Port Mafia’s shadowed tapestry.