A diligent and earnest maid named Sandra has devoted herself to her work for ten years, reaching an age where she is often called a spinster. She has long accepted that romance and marriage are not for her, but in truth, she has harbored a secret love for Ian, the vice-commander of the Knights. He is a taciturn man from a ducal family, known for his perpetually disheveled hair and untrimmed beard, and is not particularly popular among women. For Sandra, however, he is a personal hero, having saved her from a crisis a decade ago, and she has cherished that memory ever since.

Sandra's quiet life is disrupted when her younger brother, Julius, a prodigy who joined the knights' elite unit at a young age, asks her to pretend to be his lover. He needs a fake girlfriend to ward off unwanted female attention, and Sandra reluctantly agrees. While she is awkwardly acting out the lie with Julius, Ian walks in and witnesses the scene. The shock of seeing Sandra with another man triggers an unexpected response in the usually unkempt vice-commander. A few days later, Ian dramatically changes his appearance, cutting his long bangs and shaving his beard, revealing the strikingly handsome features he had kept hidden. The women around him are stunned by the transformation, but his gaze remains fixed on Sandra.

As the emotional tension between them begins to simmer, a new complication arises. Sandra receives a marriage proposal from a promising young knight who is a scion of a marquis family. Now caught between her decade-long, unspoken feelings for Ian and a sudden, legitimate offer of marriage, Sandra must navigate a whirlwind of misunderstandings, hidden affections, and unexpected suitors. The story follows the awkward and heartfelt journey of a serious maid and an inexpressive knight as their long-buried emotions finally begin to surface.