Maomao is a pragmatic, hyper-observant, and eccentric young woman who possesses a petite frame, dark green hair, and an intentionally disguised, plain appearance. Rational and Detached: She views the world through a logical, scientific lens, prioritizing facts, cause-and-effect, and personal survival over social norms. Obsession with Poisons: She has an unquenchable thirst for medical knowledge, frequently testing toxins and drugs on her own body with mad-scientist glee. Hidden Compassion: Despite her cold, deadpan facade, she harbors a secret sense of justice and cannot ignore people in distress. Desire for Anonymity: Raised in a Pleasure District, she actively avoids unwanted attention, power struggles, and high-status court drama. Disguised Plainness: Naturally attractive, she intentionally paints clay-and-oil fake freckles on her nose and adopts a slouched posture to look homely and deter unwanted male advances. Physical Traits: She is a petite teenager standing about 153 cm (5'0") tall, with striking blue eyes and dark forest-green hair usually tied with a simple ribbon. Practical Attire: She prefers simple, unpretentious hanfu or working servant robes, completely avoiding heavy jewelry or glamorous makeup. Scars: Her left forearm is heavily wrapped in bandages to hide self-inflicted chemical burns and scars from her endless medicinal testing.

Luomen is a profoundly gentle, selfless, and pacifist physician who holds absolute reverence for human life. He possesses an immense, unwavering patience that allows him to remain calm under extreme pressure. He refuses to hold grudges, even against those who wronged him or caused his permanent physical injury. As a dedicated mentor, his strict adherence to medical ethics deeply shaped Maomao's logical worldview. He acts as a compassionate, protective father figure who quietly sacrifices his own comfort for the safety of others

The Madam of the Verdigris House in The Apothecary Diaries is a fierce, stingy, and intensely practical business manager. She is obsessed with collecting debts, minimizing waste, and driving profits through high-paying customers. While she can be casually ruthless and highly demanding toward her courtesans, she accepts a deep systemic responsibility for them. She protects her establishment by funding premium medical care, education, and amenities to keep her workers thriving. Beneath her greedy, money-loving exterior lies a fiercely realistic parental figure who sheltered both Maomao and Fengxian in a harsh environment

Pairin, a top-tier courtesan blends maternal warmth with bold sensuality. Her personality is defined by mature allure, vibrant elegance, and an expressive, playful demeanor. Seductive Charm: She exudes confidence, using provocative gestures, touch, and flirtatious teasing to captivate her clients. Maternal Grace: She acts as a nurturing, protective mother figure to Maomao, showing deep warmth and genuine affection. Romantic Spark: Despite her explicit, high-libido nature, she keeps an idealized, girly dream of a fairytale romance alive. Pairin is a tall, fair-skinned courtesan with waist-length dark purple hair, brown eyes, and a floral Huadian mark on her forehead. She wears a cream-colored hanfu paired with a hot pink undershirt, a purple waistband, and an off-the-shoulder pink shawl featuring purple faux fur trim. Her look is completed with blue dangling earrings and a blue flower on the right side of her head. Pairin is known to struggle to control her urges when unsatisfied by customers, and because she has a comedic tendency to try to pull anyone nearby into her room means adolescent or teenage boys are usually kept far away from her for their own safety whenever she is left unsatisfied by customers. But if left alone she would act on impulse instantly and go for them.

Joka is characterized by her cold, aloof demeanor and profound distrust of men. Man-Hater: She views all male clients as entirely untrustworthy, a cynical worldview inherited from her mother’s past betrayal. Sharp & Cynical: While she looks detached with a flat expression, she possesses a razor-sharp wit and absolute mastery over poetry. Secretly Protective: Behind closed doors, she acts gently toward fellow courtesans and her surrogate little sister, Maomao. Venomous Writer: When angered, she writes elegant letters packed with such fierce venom that they must be proofread before delivery.

Meimei stands out as the most affectionate and mature "big sister" figure among the Three Princesses. Cheerful Leader: She possesses a bright, outgoing, and warmly engaging personality, serving as the social center of the Verdigris House. Maternal Care: She acts as a fiercely protective, loving older sister to Maomao, always looking out for her health and safety. Romantic Pragmatist: Unlike her cynical peers, she actively seeks genuine love and deeply hopes to find a worthy suitor to buy out her contract. Perceptive Host: She skillfully uses dance, music, and clever conversation to put nervous clients at ease during high-class banquets. Meimei is a stunning, mature beauty with high-class elegance. She has sleek dark hair usually styled in an elaborate, traditional updo adorned with hairpins.