The protagonist, a salaryman who died from overwork, awakens in a luxurious room in an unfamiliar world. He discovers he has been reincarnated as Sirius Ocelot, a blonde-haired, blue-eyed young man with a striking appearance. He quickly realizes he is in the world of a gal game he once played, "Azure Rosary," and has been reborn as the game's most detested villain. Sirius is the student council president of St. Bright Knights Academy, known for his cruel bullying and abuse of power. In the game, Sirius is destined to be killed by the protagonist, Rosario Gordon, as a pivotal event that triggers Rosario's true power.
Initially, the protagonist accepts his fate, intending to provoke Sirius's death quickly to move on to his next reincarnation. However, witnessing Sirius's extreme abuse of his half-sister, Luna Ocelot, deeply disturbs him. He intervenes, forcing Luna to eat at the same table as him, a stark contrast to Sirius's usual cruelty. Despite his internal conflict, he maintains Sirius's persona, believing that any kindness might alter his fated death.
At St. Bright Knights Academy, Sirius is surrounded by sycophants. He encounters Rosario Gordon being bullied by two other students, Tipo and Zapp. Though Sirius himself has a history of bullying Rosario, he intervenes, beating up Tipo and Zapp. He then cruelly tells Rosario that he is weak and should remain trampled upon, aiming to foster hatred and push Rosario towards his destined awakening.
Later, Sirius encounters Alicia von Gardennia, the third princess and a main heroine. Alicia, who despises Sirius for his cruelty, challenges him to a duel. Sirius, aware of her arranged marriage to Prince Michael of the Proteus Empire, dismisses her desire for freedom and mocks her perceived naivety. He subtly directs her towards Rosario, suggesting that true freedom comes from having nothing.
Sirius's father, Gigalt Ocelot, the head of the Ocelot family, reveals his ambition to use magic stones from the Proteus Empire for his ancient weapon industry. He orders Sirius to ensure the engagement between Alicia and Prince Michael progresses, even if it requires forceful measures. Sirius agrees, seeing this as an opportunity to further his own goals.
As student council president, Sirius announces a mandatory "Monster Hunt" in the dangerous "Twilight Forest." This event, intended to raise the students' combat prowess and generate hatred towards Sirius, is met with widespread fear and protest. Prince Michael, who has his own "script" for his relationship with Alicia, is angered by the disruption to his plans. Sirius manipulates Michael by suggesting the event will foster intimacy with Alicia, leading Michael to reluctantly accept.
Sirius struggles with his lack of Sirius's memories and his inability to use magic, forcing him to seek knowledge in the library. He is confronted by Ann Bivalent, a heroine seeking revenge for her father's murder by Sirius. Sirius easily deflects her attack, demonstrating his overwhelming power. He advises Ann to make allies and even suggests seducing men to gain power, further fueling her hatred.
Finally, Alicia confronts Sirius, accusing him of bullying Rosario and preventing their destined meeting. Sirius, realizing the game's narrative is diverging, feigns ignorance and agrees to a duel, despite his immediate need to study magic. He is determined to fulfill his role as Sirius Ocelot, even as his actions create unforeseen consequences within the game's established plot.
