In the borderlands of a fantasy kingdom, Lettie Hungaria, the teenage daughter of a margrave, has crowned herself a wicked tyrant. Every day she sets out to terrorize her subjects: she forces local orphans to run errands for her (while secretly overpaying them with change she leaves behind), she hires widows who lost their husbands to monster attacks as maids and pays them an insultingly generous salary, and she rounds up all the unemployed men to form a private army (which dramatically improves the region’s security). Lettie sincerely believes she is a villain, but every one of her “evil” acts actually improves the lives of her people and fuels the local economy.

Her routine of self‑proclaimed cruelty is disrupted when she purchases a badly burned slave at a market. To her shock, the slave is Weiss, the kingdom’s deposed first prince, who barely escaped a revolution that toppled the royal family. He reveals his identity and asks for her help reclaiming the throne. Lettie, fearing that a collapse of the kingdom would ruin her comfortable life of tyranny, agrees to protect him—but only because, as she tells herself, he would be helpless without her. She sets out to do whatever it takes to keep her peace, even if it means accidentally aiding the wretched citizenry.

As the story unfolds, Lettie’s misinterpreted good deeds keep multiplying. She uses a rare ability to “expose others’ weaknesses,” but instead of humiliating people, her straightforward critiques help them grow. She treats Weiss as a pampered bodyguard, and he becomes both devoted to her and increasingly convinced that she has a noble heart—much to her irritation. Meanwhile, her loyal butler Ashley, who hides a past as a former high‑ranking member of a mercenary group called the Hell Wolves, grows jealous of Weiss’s place at Lettie’s side. Their rivalry escalates into a chaotic duel for the position of her personal guard.

Later narrative arcs see Lettie organizing a military force of former unemployed men to defend against monsters and bandits, dealing with rising political turmoil as the revolutionary faction threatens to return, and hosting a grand costume festival that inadvertently cements her popularity even further. In every situation, she believes she is acting for her own selfish, wicked reasons, while everyone around her praises her as a benevolent leader. The series is a continuous comedy of misunderstandings, with Lettie’s attempts at villainy only strengthening the kingdom and the loyalty of her followers.