The protagonist awakens in the body of Weiss Hamilton, the "incompetent and wicked lord" from the simulation RPG "Valhalla Tactics." He realizes he has been reincarnated into the game's world, inhabiting the body of a character destined for a miserable end. His immediate goal is to prevent this fate, not just for himself, but to save his "oshi" (favorite character).
Weiss's current situation is dire: he suffers from several debilitating "bad statuses," including alcohol dependency and malnutrition, which negatively impact his stats and abilities. His most critical issue is his extremely low "public loyalty" of 10, making rebellion a constant threat. His personal maid, Rosalia, is fiercely loyal and deeply concerned for him, despite his past mistreatment. Another maid, Meg, is more cynical about Weiss's character but still performs her duties.
The protagonist, now inhabiting Weiss, immediately begins to implement changes. He uses his knowledge of the game to his advantage, starting by accessing his status screen and then resolving to improve his physical condition and address the dire state of the territory. He prioritizes eating proper meals, much to Rosalia's joy, as Weiss had been neglecting his health. He also begins to train his magic, specifically shadow magic, which he can perform with surprising ease due to his gamer knowledge and possibly Weiss's latent talent.
A major turning point occurs when a merchant named Gustav attempts to extort Weiss, demanding repayment of a significant debt and threatening to take Rosalia as collateral. Weiss, fueled by a fierce protectiveness of Rosalia, refuses Gustav's proposition. He then reveals his plan to repay the debt by retrieving hidden treasure from a secret passage within the mansion, a secret known to him from the game. He enlists Rosalia's help, and together they navigate the passage, facing and defeating monsters. During this, Weiss discovers Rosalia's exceptionally high stats and unique skill, "Devotion to Master," realizing her immense combat potential and unwavering loyalty. He also bestows upon her a protective ring, a family heirloom, and takes a magic-enhancing ring for himself.
Upon returning, Weiss confronts Gustav, revealing that he has uncovered Gustav's fraudulent activities, including price gouging and potentially illegal dealings. Weiss, with Rosalia's formidable combat prowess and his own growing magical abilities, manages to apprehend Gustav and his guards, securing the territory's finances and exposing corruption. This decisive action earns him the respect of some of his subordinates, including Kaiser, a former captain of the guard who was unjustly demoted. Weiss reinstates Kaiser and publicly declares his commitment to leading the territory effectively, promising to prove his worth through action. He also begins to address the territory's rampant crime by targeting criminal organizations, starting with the corrupt Captain of the Guard, Barbaro, whom he confronts and defeats using his shadow magic.
Throughout these events, Weiss's interactions with Rosalia deepen, revealing her profound loyalty and affection for him, which he reciprocates. He also begins to mend his relationships with other staff, like Meg, who is surprised by his changed demeanor. The narrative arc shows Weiss transforming from a reviled figure into a capable and determined leader, driven by his desire to save his "oshi" and protect those loyal to him, while actively working to improve the territory and its people's lives.
