Esmeralda, a duke's daughter, is publicly branded a villainess after being forced to take the blame for all her stepsister's malicious acts. To protect her sickly mother and young brother, she silently endures the false accusations. When her stepsister refuses an arranged political marriage to King Gregorio of a neighboring country, a monarch feared as the Bloodstained Lion King, Esmeralda is sent as a substitute bride.

Arriving at the court of the man rumored to be cold and ruthless, Esmeralda discovers a legal loophole. According to the kingdom's laws, a marriage can be annulled after three years if the couple has produced no children. Seizing this opportunity, she resolves to keep her marriage purely formal and maintain a platonic relationship to secure her freedom. However, her carefully laid plans for a quiet divorce begin to unravel on the very first night, when the intimidating king makes his intentions clear and expresses his desire to claim her as his queen in every sense.

Despite her reputation as a villainess, Esmeralda is actually a kind and principled young woman. Her attempts to act the part of a wicked, unlovable wife to discourage the king are awkward and often transparent, failing to fool the perceptive Gregorio. The king, who initially appears cold, proves to be a capable and just ruler. He becomes intrigued by his new bride and sees through her facade, growing determined to capture her heart and prevent the annulment she so desperately seeks. The narrative follows their evolving relationship, filled with romantic misunderstandings and physical tension, as Esmeralda struggles between her goal of a divorce and her growing feelings for her husband.

The story is set in a fantasy European-style aristocratic world, focusing on the political dynamics of the two neighboring kingdoms. Esmeralda's life is complicated by the cruel schemes of her own family, including her wicked stepsister and stepmother, while at the king's court, she must contend with other hostile figures like the queen mother. As the three-year timeline progresses, the pair works together to overcome court conspiracies and cleanse the kingdom of corruption, deepening their bond and forcing Esmeralda to reconsider whether she truly wants to leave her marriage after all.