Stella is a thirty-year-old econometrician who excels at statistics and modeling but struggles with social and romantic interactions due to her Asperger's syndrome. She views the world logically and analytically, finding comfort in data and reliable routines. Pressured by her family to date and eager to overcome her aversions to physical intimacy, she decides to hire a professional to teach her.

Michael is a handsome, muscular man of Vietnamese and Swedish descent who uses the alias Phan during his Friday night escort appointments. He spends the rest of his week working at his family's dry-cleaning and tailoring shop, taking on immense financial burdens to support his ailing mother. Despite his physical confidence, he harbors deep insecurities about his intellect and moral character, largely stemming from his strained relationship with his estranged father.

Phillip is a conventionally attractive econometrician who works in the same office as Stella. While he shares her professional background, he exhibits a blatant disregard for personal boundaries and frequently exploits the women around him. He makes inappropriate comments about Stella's personal life, serving as the catalyst for her decision to seek out professional dating practice.

Quan is Michael's cousin on his mother's side, balancing his studies in business school with shifts at his family's restaurant. Covered in tattoos and practicing martial arts, he presents an intimidating exterior that contrasts heavily with his highly observant and supportive nature. He serves as a vital sounding board for Michael, helping him manage his complicated personal life.

Ann, affectionately known as Mẹ, is Michael's optimistic and loving mother. Despite battling a serious, costly illness, she remains heavily involved in her children's lives and refuses to let her health struggles dampen her spirit. She is a welcoming matriarch who prioritizes her children's happiness above all else, maintaining hopefulness even when facing significant physical hardships.

Frederick is Michael's estranged father, an attractive man of Swedish descent whose past actions heavily influence the Larsen family's present circumstances. He is an absent figure who previously demanded excellence from his son, specifically pushing him away from his passions in favor of more practical pursuits. His legacy of broken trust hangs over the family.

Janie is Michael's younger sister, an economics student at Harvard whose academic performance suffered following her mother's health diagnosis. She is deeply integrated into the loud, loving dynamic of the Larsen household and shares a playfully affectionate relationship with her brother.

Edward is Stella's father, a strict and protective man who places a high premium on professional achievement and social standing. He maintains lofty expectations for his daughter's life, particularly concerning the type of partner he believes is suitable for her.

Ann is Stella's mother, an active organizer of charity fundraisers who deeply desires grandchildren. While she struggles to fully understand her daughter's sensory aversions and boundaries, she genuinely wants Stella to find happiness and a partner who complements her unique needs.

Ngoại is Michael's grandmother, a steady presence in the multigenerational Larsen household. She contributes to family conversations and daily chores, bringing a traditional perspective to the family dynamic while fully supporting her grandson's happiness.

Khai is Quan's younger brother, an autistic young man who shares certain behavioral similarities with Stella. His presence in Quan's life provides his family with a strong understanding of autism, which influences how they interact with others on the spectrum.

Aliza is an extremely wealthy former client of Michael's who struggles to respect the boundaries of their past professional arrangement. She is accustomed to using her financial influence to maintain connections and views Michael with an aggressive sense of possessiveness.