The story opens with a flashback to five-year-old Cecilia, excited for an arranged marriage with Henry, the handsome son of her father's friend. Henry, however, immediately insults her appearance, calling her "ugly" due to her dark hair and freckles, and throws mud on her favorite blue dress. Her father, a successful tea merchant, dismisses Cecilia's feelings, agreeing she lacks beauty but praising Henry's bluntness as suitable for business. Henry reluctantly accepts the engagement, leaving Cecilia heartbroken and developing a deep aversion to blue skies.
Fifteen years later, twenty-year-old Cecilia still views herself as plain, despite being highly intelligent and diligent. She works as a royal palace maid, a prestigious position earned through academic merit. On her daily commute, she encounters Baldo, a kind man with a golden beard and blue eyes, whom she perceives as an older gentleman. Baldo, a royal chef, regularly shares homemade sweets, and Cecilia, in turn, writes him detailed thank-you letters.
On her day off, Cecilia assists at her family's thriving Rupert Trading Company, showcasing her fluency in foreign languages. Her father, however, continues to pressure her about her "lack of beauty," insisting she marry Henry and quit her maid job. Her younger sister, Lilia, a kind and pretty fifteen-year-old, often defends Cecilia. Henry, now a handsome young man, picks Cecilia up for a "date" but quickly abandons her for another woman, Laura, openly insulting Cecilia and demanding money.
Distraught, Cecilia retreats to a cafe where Baldo joins her. He offers her a nut tart, revealing his keen observation of her preferences. Baldo then shares a personal story about choosing one's own path, emphasizing that happiness comes from striving on a self-chosen journey. This deeply impacts Cecilia, causing her to cry as she realizes her unhappiness. Baldo, surprisingly, reveals he is only twenty-five.
Later, Maid Chief Karen informs Cecilia that her father has submitted a resignation letter on her behalf, but Karen refuses to accept it without Cecilia's direct consent. Baldo, noticing Cecilia's distress, takes her to the royal garden, offering comfort. Cecilia confesses her self-hatred, and the image of Henry comes to mind as something she dislikes. She cries again, acknowledging her desire to continue her maid work.
That evening, at a family dinner with Henry, Cecilia's father announces the wedding date and confirms he sent the resignation. He dismisses Henry's blatant infidelity as "a man's courage" and blames Cecilia for not quitting her job. Remembering Baldo's words, Cecilia finds the courage to refuse the marriage, declaring it is not her path to happiness. She confronts her father and Henry, calling Henry "scum." Lilia, inspired, announces her intention to inherit the company with "Grandis-sama." Enraged, her father disowns Cecilia, who calmly accepts and leaves the house, feeling liberated.
Cecilia moves in with her grandmother in a distant village, enduring a long, early morning commute. Baldo, concerned for her safety, helps her find an affordable boarding house near the palace, owned by the quirky Madam Linda. To Cecilia's surprise, Baldo's room is right next to hers.
Meanwhile, the story introduces Catherine Castall, a Marquis daughter whose engagement to Duke's heir Raymond was publicly broken off in the academy hallway. Raymond, declaring love for Baron's daughter Mimi, was subsequently disinherited and forced to marry into Mimi's family by the King. Catherine, however, secretly rejoices, revealing an inner monologue where she possesses past-life memories and views this world as an "otome game" side story. Her true goal is to become a maid for Elizabeth Langardov, the Crown Princess, whom she idolizes as her "oshi."
Catherine, despite her noble status and enthusiasm, is utterly clueless about basic maid tasks, causing two previous maid leaders to "fall ill" after attempting to train her. Maid Chief Karen then assigns Cecilia to mentor Catherine. Cecilia, a seasoned maid team leader, patiently begins teaching Catherine, who doesn't even know what a rag is. During a cleaning session, Catherine accidentally spills soapy water and slips, nearly colliding with the elegant Crown Princess Elizabeth.
Cecilia immediately takes responsibility, pulling Catherine into a deep bow. Elizabeth's maid, Rosalie, a prejudiced commoner-hater, slaps Cecilia. Elizabeth, however, intervenes, challenging Rosalie and Cecilia to a knowledge contest: reciting the names of past kings. Cecilia, determined to protect Catherine's future, accepts and flawlessly recites numerous royal names, while Rosalie struggles and ultimately fails. Elizabeth dismisses Rosalie for her arrogance and lack of knowledge. Cecilia, despite her injured cheek, prioritizes Catherine, explaining that it is her duty as a maid team leader to ensure Catherine's success. Catherine, deeply moved, reveals her "oshi" devotion to Elizabeth and pledges loyalty to Cecilia, calling her "onee-sama." Cecilia, now confident and empowered, encourages Catherine, no longer burdened by her past, and embraces her chosen path.
