Agnes Evantail, the eldest daughter of the House of Evantail, is the laughingstock of high society. Ridiculed as a Lady Bumpkin for her family’s insistence on outdated makeup, antiquated clothing, and old-fashioned manners, she has endured failed engagement attempts and the physical and emotional abuse of her parents for as long as she can remember. At yet another humiliating social function meant to find her a husband, she is the sole witness to a stunning betrayal. Princess Mia, the fiancée of the perfect and kind Nazelbart Florescruz, publicly accuses him of villainy to cover up her own affair and pregnancy, resulting in his exile to the remote frontier territory of Sutrena. In a fit of pique, the princess punishes the sympathetic Agnes by forcing her to marry the disgraced lord and join him in banishment.

Cast out and disowned by her own family, Agnes travels with Nazelbart to the desolate frontier. There, she begins to shed the oppressive trappings of her former life, revealing both her natural beauty and a hidden talent for powerful magic previously dismissed as useless. Together, the unlikely couple works to win over the distrustful residents of Sutrena, who have suffered under a cruel previous lord, and build a peaceful, happy life. However, trouble continues to brew in the capital. Princess Mia’s lover, a charismatic man named Robin, uses his charm and vague mind-control abilities to seduce noble ladies, destroying their engagements and ruining their lives. One such victim, Liliane, flees to Sutrena and attempts to assassinate Nazelbart, forcing Agnes to confront the rot at the heart of the kingdom’s nobility.

As Agnes and Nazelbart navigate their growing feelings for one another and plan a proper wedding ceremony, they become entangled in a web of corruption, abuse, and dark secrets that pervades their world. The narrative follows their efforts to expose villains like Robin, rescue victims of noble malfeasance (many of whom end up finding a new home as maids in Agnes's household), and revitalize their frontier territory. Later arcs see the tables turned on Princess Mia, who is exiled to a prison island where she unexpectedly begins to reform, as well as a journey to a neighboring kingdom where Agnes’s true identity as a legendary saint is heavily hinted at, all while she deals with the complications of pregnancy and fending off jealous suitors.