The story begins with Delilah Estrada, the newly appointed Border Count of Estrada, receiving an unexpected royal decree: she is to marry Prince Ophir of Ophyr. Initially angered by the arbitrary decision, Delilah's anger turns to surprise when she learns the marriage comes with a substantial dowry. Her territory, Estrada, is a crucial defense against the monsters emerging from the vast, adjacent Demon Forest, a threat that claimed her father's life. The King's decree also absolves Delilah of any responsibility should the Prince be harmed by monsters, a detail she notes with a hint of amusement, especially given the Prince's rumored limited healing magic and the fact that the second prince has already ascended to Crown Prince. Her loyal childhood friend and subordinate, Liner, expresses concern about the marriage, particularly given the Prince's past scandal at the academy involving a Baroness and the subsequent anger of a Duke's family. Delilah, however, sees the dowry as a means to rebuild her war-torn lands and acquire much-needed supplies, dismissing the Prince as a "boring man" for his alleged romantic entanglement rather than a more serious offense.
Upon arriving at the Estrada territory, Prince Ophir is struck by its grim, muted atmosphere, a stark contrast to the vibrant capital. He is met by Delilah, whose striking purple hair and eyes stand out against the desolation. Their initial interaction is blunt, with Delilah questioning his absence of the Baroness he was infatuated with. Ophir, despite the Prince's seemingly unimpressive demeanor and his sidekick Lloyd's outrage at Delilah's perceived disrespect, finds her surprisingly direct rather than malicious. Delilah, in turn, notes his golden hair and eyes, a detail that strangely evokes a sense of unease. Their marriage is agreed upon with a handshake and a warning from Delilah to remember where she is. Ophir, initially skeptical of Delilah's legendary dragon-slaying prowess, begins to see the truth in it through her powerful presence and calloused hands. Their brief encounter is interrupted by the sound of approaching monsters, signaling an imminent attack. Delilah, unfazed, quickly signs the marriage papers before rushing off to defend her territory, leaving Ophir bewildered by her abrupt departure.
Ophir and Lloyd witness Delilah's swift and brutal dispatch of a large, horned monster, revealing the true extent of her combat abilities. Lloyd is astonished, while Ophir, having only seen smaller monsters before, is equally impressed. Delilah's prowess in battle is evident as she moves with incredible speed and agility, easily felling the creature. Ophir reflects on the rumors of her ferocity and cruelty, realizing they are false. He also learns that Delilah's family has been instrumental in protecting the kingdom from monster incursions.
Later, Delilah and Liner discuss the Prince's arrival. Delilah finds him less imposing than expected, noting his refined appearance and resigned demeanor, suggesting he is a prince who lost a power struggle. She had anticipated a more arrogant figure and planned to assert Estrada's customs. Ophir, however, shows genuine interest in the monster carcasses and asks practical questions about their disposal, demonstrating a willingness to adapt. Delilah explains that the dowry, which she believed was solely from the King, also included Ophir's personal assets, revealing the King's stinginess. She begins to see Ophir as someone she might be able to coexist with, appreciating his efforts to integrate.
A week later, Delilah confronts Ophir about the disrespectful behavior of his retainers, who are looking down on the Estrada staff and territory. She declares that insulting Estrada is equivalent to insulting the soldiers who died defending it, threatening severe consequences. Ophir, though initially hesitant, promises to investigate. Lloyd, Ophir's loyal attendant, interjects, defending the Prince and questioning the need for etiquette in the harsh borderlands. Delilah, exasperated by their perceived arrogance and lack of understanding of the border's realities, decides to teach them a lesson by throwing them into the edge of the Demon Forest. Ophir, surprisingly, volunteers to go with them. The experience proves to be a harsh but effective lesson for the retainers, who are terrified by even the weakest monsters, while Ophir remains unharmed. This incident leads to an improvement in the retainers' attitudes.
Their relationship develops into a more cohabitative arrangement, with shared meals and activities, though their rooms remain separate. Delilah, believing herself infertile due to a dragon's curse, sees no need for intimacy. However, when Serva, a loyal subordinate, is poisoned by a rare monster, Ophir unexpectedly uses his healing magic, revealing a power far beyond what he had previously shown. He successfully heals Serva and two other injured soldiers, though the exertion causes him to collapse. Lloyd reveals that Ophir had been hiding the extent of his healing abilities to avoid exploitation by the King and Queen, who had been targeting him. Ophir's willingness to use his power for the soldiers, despite his own past betrayals and weariness, impresses Delilah, who begins to see him in a new light.
Ophir recovers and Delilah expresses her gratitude for his actions, noting his unusual politeness. He admits he was drawn to her strength and sacrifice, and that he used his magic because he wanted to protect her. Delilah, initially dismissive of him as a "chick" and a mere "paper husband," finds herself touched by his sincerity and the fact that he risked himself for her. She realizes her own cynicism and resignation, contrasting it with his quiet determination.
Later, a letter arrives from the King, summoning Ophir back to the capital to use his healing magic. Lloyd reveals that the second prince's reputation is tarnished, and some factions wish to reinstate Ophir. Delilah, aware of the potential danger, offers Ophir a divorce, suggesting he remarry a suitable noblewoman and become king. However, Ophir, influenced by Delilah's example and his growing feelings for her, refuses to abandon her. He confesses his desire to protect her and stay by her side, even if it means defying the King.
Meanwhile, a dragon attacks the Estrada territory. Delilah, despite her own dragon curse, fights bravely, using newly acquired explosives to defeat it. She reflects on her past and her brother's sacrifice, realizing that Ophir, despite his perceived weakness, possesses valuable qualities and a genuine desire to protect her. She accepts his offer to stay by her side, acknowledging her own feelings for him.
