Tasha is the mother of the protagonist, Lilly, and Rachel. She works as a successful real estate agent and is the primary authority figure in the household. Her core relationships are with her children and her sister, Christine.

Tasha has a fit, athletic body, maintained through regular yoga and gym workouts. She has auburn hair, light eyes, and a curvy figure. She is often seen wearing nightgowns, lingerie, or casual loungewear around the house.

Tasha is initially portrayed as a firm, responsible, and slightly conservative mother. However, she is also emotionally open and vulnerable, especially when it comes to her children and sister. Deep down, she harbors repressed desires and a latent jealousy, which are triggered by her discovery of her children’s secret sex life. She is pragmatic and eventually accepts the situation to maintain family unity, showing a capacity for great flexibility and even enthusiasm once her barriers are lowered. Her primary defense mechanism is denial and avoidance, which she eventually discards.

A single night of drunken experimentation with her sister, Christine, in their college dormitory, which she remembers with a mix of embarrassment and fondness. Walking in on the protagonist and Rachel having sex, which forces her to confront the reality of her children's secret lives and shatters her illusion of a normal family. [Core Bond] The moment she confesses her jealousy and kisses the protagonist, admitting her attraction to him. This transforms their relationship from parent-child to a romantic and sexual one.

Lilly is the protagonist's younger sister, a high school graduate about to enter college. She works as a waitress. Her core relationships are with her brother, her sister Rachel, and her mother Tasha. She is highly competitive with Rachel.

Lilly has a fit, slim, and youthful figure. She has long dark hair and is often seen in trendy, revealing outfits, including bikinis and lingerie. She is the most fashion-conscious of the sisters.

Lilly is impulsive, sexually forward, and deeply curious. She initially uses sex as a tool for experience and rebellion, but she quickly becomes the primary instigator of the protagonist's affairs. She is manipulative, often orchestrating situations to advance her sexual goals, and enjoys the taboo aspect of her actions. She is confident, almost to the point of arrogance, and lacks the moral reservations that plague Rachel. Her primary defense is her bravado and carefree attitude.

Her decision to go to the graduation party with the specific intention of losing her virginity, highlighting her proactive and goal-oriented nature. The moment she reveals to Rachel that she is not only not ashamed but actively wants to continue the affair, showcasing her complete embrace of the taboo. [Core Bond] Her first sexual encounter with the protagonist at the party, which breaks the familial barrier and establishes their secret relationship.

Rachel is the protagonist's older sister. She works at a clothing store and is portrayed as the most mature and responsible of the siblings. Her core relationships are with her brother, her sister Lilly, and her mother Tasha.

Rachel has a mature, attractive, and athletic build. She has light-colored hair and is often seen in comfortable but flattering casual wear or her work uniform. She is less flashy than Lilly but equally attractive.

Rachel is initially the most conflicted character, torn between her strong moral compass and her hidden desires. She is the family's "straight man," often reacting with exasperation or disgust to Lilly's antics. She is pragmatic, careful, and highly concerned with consequences. However, she has a repressed and adventurous side that she eventually reveals. Her primary defense mechanism is denial and projecting an image of propriety.

Rachel's decision to take birth control pills despite having no boyfriend, revealing her subconscious preparation and desire for sexual encounters. The "accidental" sexual penetration in the car, which overwhelms her moral defenses and serves as the catalyst for her route. [Core Bond] Her confession to the protagonist that she wanted him before the car incident, and her admission that she enjoys the secret relationship, solidifying her acceptance.

Christine is Tasha's sister and the protagonist's aunt. She is a free-spirited, impulsive woman who recently lost her home (a yacht) and is staying with the family. Her core relationships are with her sister Tasha and her nieces and nephew.

Christine is an attractive, fit woman with a youthful appearance. She has a carefree style and is often seen in minimalist clothing, often wearing just a robe or lounging wear.

Christine is hedonistic, impulsive, and often acts as a co-conspirator and provocateur. She is emotionally intelligent and sees sex as a form of fun and freedom. She is pragmatic, easily reading people’s desires, and is not ashamed of her own sexuality. She is a natural leader, often giving advice and orchestrating events for her own amusement. Her primary defense is her unpredictable and confrontational nature, which makes her difficult to pin down.

A story she tells about having a drunken one-night stand with her sister, Tasha, in college, which established her as someone who blurs familial boundaries. Her discovery of the protagonist's incestuous relationships and her immediate decision not to judge but to participate, marking her as a key ally. [Core Bond] Her offer of a "boobjob" to the protagonist in exchange for a secret, solidifying their sexual and conspiratorial relationship.

Maya is the protagonist's tutee and casual girlfriend. She lives with her aunt, Eileen, as her parents died in an accident. Her core relationships are with the protagonist, her aunt Eileen, and her tutor Mandy.

Maya is a young, attractive girl with a stylish, modern aesthetic. She is often seen in casual clothing like rompers and is described as having a great body.

Maya is flirty, open-minded, and sexually confident. She is proactive in pursuing the protagonist and is not easily shocked. She enjoys sexual novelty and is willing to explore, as seen when she sets up a threesome. She is independent and unbothered by the protagonist's other relationships. Her primary defense is her ability to compartmentalize and not take things too seriously.

The death of her parents in a car accident, which explains her living situation with her aunt Eileen and gives her a vulnerable side. Her initiation of the first sexual encounter with the protagonist, which sets the tone for their casual, sexual relationship. [Core Bond] Her willingness to help the protagonist by letting him stay at her house when he is kicked out, demonstrating her loyalty.