Maomao (猫猫) Female Age: 17 Hair / Eye Color: Dark Green / Green Background: An apothecary raised in the Verdigris House of the Pleasure District. After being kidnapped and sold into the Inner Court as a laundry maid, her exceptional pharmaceutical knowledge and deductive reasoning lead her to become Lady Gyokuyo's lady-in-waiting and food taster. Personality: Cold, stoic, and keeps others at a distance. However, she displays a near-maniacal obsession when it comes to medicine and poisons. Features: Her freckles are a disguise she paints on to avoid trouble in the Inner Court. She has scars and bandages on her right arm from testing poisons on her own body.

Jinshi (壬氏) Male Age: 19 (Publicly claims to be 24 in his eunuch persona) Hair / Eye Color: Dark Chestnut with a purple tint (or Indigo-Purple) / Purple Background: The administrator in charge of the entire Inner Court and a eunuch. In reality, he harbors a massive secret identity as the Emperor's younger brother (and heir to the throne). Personality: Kind and charming on the surface, but internally calculating, he actively utilizes his seductive beauty to manipulate others. Features: A peerless beauty often compared to a celestial maiden. Unlike most women who are obsessed with him, he is shocked by Maomao, who looks at him with utter disdain as if he were a bug, and gradually falls truly in love with her.

Gaoshun (高順) Male Age: 36–37 Hair / Eye Color: Black / Black Background: The head of the Ma family, a lineage of military officials, and a high-ranking official himself. He has entered the Inner Court disguised as a eunuch to assist Jinshi under imperial orders. Personality: Taciturn, serious, and extremely diligent. Features: He looks after Maomao and calls her 'Xiao Mao.' A married man with children and even grandchildren, he acts as a bridge and a voice of reason when Jinshi gets ahead of himself regarding Maomao.

Lady Gyokuyo (玉葉 妃) Female Age: 19 Hair / Eye Color: Pink / Jade Background: The Precious Consort (Guifei) among the four high-ranking consorts of the Inner Court. A princess from a foreign land, she scouts Maomao as her lady-in-waiting after Maomao saves her infant daughter. Personality: Wise, intelligent, kind, and generous toward others. Features: A romance enthusiast who notices the strange tension between Jinshi and Maomao and enjoys teasing them about it.

Fengxian (鳳仙) Female Age: Late 30s to early 40s (Severely ill) Hair / Eye Color: Green / Pink Background: Formerly the top-ranking courtesan who once dominated the Rokujokugi. She is Maomao's biological mother. Personality: Possesses immense pride. Features: Her status plummeted due to an incident with Lakan, and she was forgotten as syphilis ravaged her nose and body. She truly loved Lakan. Recently, she was redeemed from the pleasure district by Lakan thanks to Maomao's intervention.

Kan Lakan (漢 羅漢) Male Age: Early to mid-40s Hair / Eye Color: Black / Black Background: A key defense official who controls the military. He is Maomao's biological father and Kan Luomen's nephew. Personality: A strategist who uses others to achieve his goals. Features: He suffers from prosopagnosia (face blindness), seeing people's faces as 'shogi pieces.' The only exceptions whose expressions and faces he can see clearly are his past love, Fengxian, and his daughter, Maomao. He is obsessively devoted to Maomao, but she treats him strictly like a pest.

Male Age: Late 50s to early 60s Hair / Eye Color: Black mixed with white / Gentle Brown Background: A former court physician who was expelled and subjected to corporal punishment after being caught up in a past imperial incident. He is Maomao's adoptive father and great-uncle (Lakan's uncle). Personality: Benevolent, kind, and possesses a deep sense of duty as a doctor. Features: A top-tier physician of his era who even learned advanced Western medical techniques. He is the mentor who taught Maomao pharmacy, medicine, literacy, and deductive reasoning. He walks with a limp in one leg.

Age: Mid to late 30s Hair / Eye Color: Black / Black Background: The supreme ruler of the country. Publicly Jinshi's older brother and the husband to the women of the Inner Court, including Lady Gyokuyo and Lady Lihua. Personality: A wise ruler who governs well. While he is jovial and warm-hearted, he also has a mischievous side and a reputation as a philanderer who loves women. Features: He has a thick, impressive beard and a sturdy physique. He genuinely cares for the women of his harem and particularly likes Maomao's outstanding abilities and eccentric personality, often requesting her to solve incidents or prepare special medicines.

Lihaku (李白) Male Age: Early to mid-20s Hair / Eye Color: Blue / Blue Background: A vigorous and capable young military official. Personality: Cheerful, simple, and straightforward.

Lady Lihua (梨花 妃) Female Age: Around 22 Hair / Eye Color: Dark Navy / Red Background: The Virtuous Consort (Xianfei) among the high-ranking consorts. Hailing from a powerful prestigious family, she was originally the head consort who gave birth to the Crown Prince. Personality: Full of dignity, she is naturally of excellent character and very warm-hearted. Features: She lost her child and nearly died herself due to lead poisoning from cosmetics (white powder), but after being saved by Maomao's nursing and blunt advice, she feels a deep sense of gratitude toward her.