Normal college student Kazuki Hirasawa wakes up inside the body of Harold Stokes, the most hated villain from his favorite video game, Brave Hearts. This is not a desirable situation, as Harold is a cruel, arrogant nobleman fated to be killed by the game's hero. Kazuki finds himself trapped in a world where every action that aligns with the original story plants a death flag, a narrative event that pushes him closer to his inevitable doom. To make matters worse, the body he now inhabits alters his speech, twisting any kind or polite intention into Harold’s signature harsh and venomous tone. Despite his genuine desire to be helpful, his words constantly earn him hate points and deepen his villainous reputation.

The story is set in a fantasy world governed by the logic of an RPG. Harold is the ten-year-old heir to the Stokes family, a noble house that prioritizes pure bloodlines and looks down on commoners. The original Harold committed terrible acts, including the murder of a maid and her daughter. The first major challenge Kazuki faces is this very event. After convincing his parents to let him use a new spell on the condemned maid, he secretly orchestrates her escape with the help of the family butler, Norman. By faking her death, Kazuki hopes to save the woman while preserving the main story's flow, as her daughter, Colette, is the game’s heroine who must eventually meet the hero.

Norman is one of the first to notice a change in the young master, seeing a hidden glimmer of care beneath Harold's harsh exterior and hoping he can reform the Stokes family. Kazuki practices magic and uses his knowledge of the game to improve the territory’s failing agriculture, creating a life potion to boost crop growth. He also begins training with a sword, knowing he will need strength to survive the battles ahead. His most complex challenge arrives with an arranged marriage to Erika Sumeragi, a girl from a prestigious family whose lands are being overrun by a deadly miasma. In the original game, she was destined to leave Harold for the hero’s party.

Kazuki decides that the best way to survive is to make Erika despise him so she will leave, while secretly providing her family with the solution to their miasma problem. However, Erika proves perceptive and begins to see through his cruel demeanor, recognizing his harsh words as a mask for genuine, self-sacrificing actions. The narrative follows Kazuki’s tightrope walk as he tries to divert his own terrible fate without derailing the hero's journey, which is necessary to save the world from its final boss. Every attempt to do good is filtered through the villainous persona of Harold Stokes, creating a conflict where his best intentions are constantly misunderstood by the public, yet sometimes glimpsed by those closest to him.