A young woman from the countryside meets an untimely end after a monster attack. Frustrated with her ordinary, unfulfilled life, she wishes for a second chance with purpose, like the characters in her favorite stories. Her wish is granted, but with a cruel twist: she awakens as Suraya, the villainess of a fantasy book she once loved. Now reborn as a noble daughter, she realizes her new identity is fated for a brutal bad ending. According to the original plot, she will lose her fiancé to the story's heroine, be publicly humiliated, and eventually join forces with the Demon King only to be betrayed and killed by him.

Refusing to accept this tragic fate, Suraya decides to use her foreknowledge of the story to fight back. Her strategy is straightforward: she must become powerful enough to survive any threat, even surpassing the final boss. She trains relentlessly, determined to rewrite her destiny through sheer strength. However, the plot veers off the expected course almost immediately. When she encounters the Demon King, he does not propose the alliance that leads to her doom. Instead, he offers her a proposal of marriage, opening an entirely unknown story route that was never in the original book.

The story is set in a world of noble academies, royal politics, and looming magical threats. At school, Suraya is forced to navigate a complex social landscape where she was originally meant to be the antagonist. Yet using her knowledge from her past life, she manages to befriend her predetermined enemies, including the story's heroine and even the Evil King. These unexpected alliances become crucial as she works to avoid her grim fate.

A major narrative arc follows her attempt to capture the heart of Seika, the last "brave man" and a capture target shrouded in mystery. Searching for him forces Suraya to delve into the dark secrets of the academy, which unexpectedly connects to a hidden resurrection route for the Demon King. This path leads to a new crisis: the Demon King, Satan, makes a complete resurrection, threatening a destruction end far worse than the one Suraya originally feared. Now, she must join forces with the very people she was supposed to oppose, including the Holy Woman, to stand against this apocalyptic threat and secure a completely new future for herself.