The series follows a young girl named Xiaolan, who at the age of thirteen is sold by her impoverished family from a struggling rural village and sent to work in the imperial rear palace. The story begins with her departure from home, capturing both the hardship of her circumstances and her remarkably resilient, forward-looking nature. Rather than dwelling on her misfortune, Xiaolan focuses on the positive aspects of her new life, such as having enough to eat and wearing the same uniform as everyone else. She is assigned to the laundry and other menial tasks, where she endures the harsh conditions of lower servant life with a cheerful disposition.

The narrative is structured as a close counterpart to the main series, The Apothecary Diaries, but told entirely from Xiaolan's point of view. It retraces key events and mysteries that unfold in the rear palace, showing how they appear to an ordinary, uneducated servant rather than to the exceptionally perceptive Maomao. Through her warm and talkative personality, Xiaolan becomes a natural gatherer of rumors and information, which she unknowingly provides to Maomao. Their friendship is a central pillar of the story, depicted with a softness that highlights Maomao's rarely seen gentle side.

The only major original character introduced is a young eunuch known as Yaku, who has a deceptively delicate appearance and a rough past as a former slave. Initially treated dismissively by other eunuchs, he develops a protective attitude toward Xiaolan after she helps him in a difficult situation. He displays a shrewd and sometimes rebellious nature when away from her, adding an undercurrent of tension and potential future conflict to the otherwise lighthearted narrative.

A notable stylistic choice in the manga is that Xiaolan's dialogue is written entirely in hiragana, visually reinforcing her illiteracy and the educational gap between her and the characters who can read and write. As the story progresses, her growing desire to learn and improve herself becomes a significant element of her character development, with her friendship with Maomao serving as a catalyst for her education. The series offers a ground-level view of palace life, emphasizing the small joys, daily struggles, and personal growth of a kind-hearted girl navigating a world of rigid hierarchy and hidden schemes.