A sickly girl named Kyoko spends her short life devoted to her favorite otome game, Magic and Lover, better known as MajiLaba. Her deepest wish is to be reborn as the proud villainess Anna Marie so she can live quietly beside Anna's older brother, Heathcliff, a character she adores but who is only available for a friend ending in the original game. When Kyoko finally passes away, her reincarnation wish is granted—but not in the way she hoped. Instead of becoming the villainess, she wakes up as Lisa, the game's bright and beloved heroine.

Now in a magical academy setting, Lisa possesses overwhelming light-attribute magic and finds herself in a comfortable, lucky position as the story's natural protagonist. But this is not what she wanted. Her original plan—to be Anna Marie's sister and avoid all drama—is impossible. Determined not to let the game's script destroy the villainess or keep Heathcliff out of reach, Lisa decides to actively change the storyline. She becomes best friends with Anna Marie, helps maintain the villainess's engagement to the prince, and works to deflect every flag that would lead to Anna's ruin. Her actions succeed so well that the original narrative bends in unexpected ways.

Along the way, Lisa discovers that Heathcliff, who was meant to be a mere guide character, might have a hidden depth and a possible love route after all. However, the story's forced events keep intervening: early appearances of antagonists like the demon Elliott, a missing magic seal, and the looming threat of a demon lord push both the heroine and the villainess's family into danger. Lisa's light magic and knowledge of the plot allow her to protect her loved ones, but she also learns that Heathcliff carries a secret—a forbidden dark magic that society despises, which explains his original friend-only role. This secret threatens to repeat the game's tragic outcomes unless Lisa can overcome both external enemies and the story's own inertia.

As the school years progress, Lisa navigates magical festivals, tea parties, casino battles, and the final confrontation with Elliott, all while carefully steering Heathcliff away from isolation and suspicion. The biggest shock comes when the original game's arranged marriage event between Anna Marie and Prince Stefan triggers a public engagement-breaking scene—a flag Lisa thought she had erased. She throws herself into preserving the duke family's honor and deflecting the disgrace that would ruin Anna and Heathcliff. Each successfully thwarted disaster brings her closer to an unprecedented ending: a genuine romantic relationship with the man who was once only a background character. The series follows her determined, often comedic struggle to bend fate, armed with nothing but her memory of the game and a fierce, single-minded love.