Kami is a high school senior living in the small town of Carsville. She maintains a carefully constructed public image of perfection, heavily directed by her mother's strict expectations, which includes dressing impeccably and cheering for the local squad. Privately, she carries immense guilt over a childhood secret that fractured her family's relationship with the neighboring Di Bianco family. She uses drawing as a hidden emotional outlet and struggles to suppress her resurfacing feelings when her former friends return to town.

Thiago is a twenty-year-old who takes a job as the high school's assistant basketball coach and detention supervisor. He is heavily burdened by his family's past tragedies and directs intense anger toward Kami, holding her entirely responsible for the events that destroyed his childhood. Despite his hostile outward behavior and strict enforcement of rules at the school, he demonstrates a strong protective instinct toward his mother and brother.

Taylor is a high school senior and the newly appointed captain of the Carsville basketball team. Unlike his older brother, Taylor refuses to blame Kami for the shared childhood tragedy and actively works to rebuild their connection. He is an outgoing, athletic student with ambitions to attend Harvard, offering Kami a stable source of comfort while openly pursuing a romantic relationship with her.

Anne is Kami's mother, a woman deeply concerned with social status and maintaining an illusion of upper-class perfection. She dictates Kami's diet, wardrobe, and social circle, actively encouraging her daughter's relationship with the mayor's son. She strictly forbids interaction with the Di Bianco family to protect long-held secrets and relies on punishment to control household dynamics.

Roger is Kami's father, a lawyer who manages finances for the mayor and other wealthy Carsville clients. He is frequently away on business trips and generally avoids domestic disputes, allowing his wife to control the household. As his company faces severe financial trouble involving embezzlement, his inability to maintain the family's lifestyle adds pressure to the household dynamics.

Danny is the mayor's son and Kami's boyfriend of two years. He initially appears as a popular, socially acceptable partner who fits Anne Hamilton's rigid expectations. When Kami ends their relationship to focus on herself, he reacts with verbal cruelty, physical intimidation, and vindictive behavior, using his family's financial influence to avoid consequences at school.

Julian is a new student at Carsville High who quickly becomes an observant ally to Kami. As an outsider, he easily reads the complex social dynamics of the school and the unspoken tension between Kami and the Di Bianco brothers. He confides in Kami about his sexuality, establishing a bond built on honesty rather than the town's typical social performances.

Cameron is Kami's energetic six-year-old brother. He provides Kami with an opportunity to show her nurturing side, as she frequently acts as his primary caretaker when their parents are absent or arguing. His innocence contrasts sharply with the tense, secret-filled environment of the Hamilton household.

Ellie is Kami's best friend and a fellow cheerleader at Carsville High. She provides a sounding board for Kami regarding school rumors and social events, though Kami keeps her most painful family secrets hidden even from her.

Kate is a cheerleader at Carsville High who harbors deep resentment toward her half-brother, Julian, masking her hostility behind a pleasant public attitude. She frequently clashes with Kami over the cheerleading squad's discipline and routines.

Katia is Thiago and Taylor's mother, a woman heavily burdened by past tragedy and depression. She works overtime shifts at a local hospital to support her sons while privately mourning the loss of her young daughter. She treats Kami with unexpected warmth and baked goods, seemingly willing to bridge the gap between their divided families.

Travis is the absent father of Thiago and Taylor whose past actions severely damaged both the Di Bianco and Hamilton families. He no longer lives with his sons, leaving Thiago to take on heavy responsibilities as the family's primary protector.

Lucy is Thiago and Taylor's deceased younger sister, whose tragic death at age four remains the central wound for the Di Bianco family. Her perfectly preserved childhood bedroom serves as a constant physical reminder of the grief her mother and brothers carry.

Coach Klebb is the head basketball coach at Carsville High who hires Thiago as an assistant. Rumors of his impending retirement create an opening that Thiago hopes to fill permanently, making Klebb's approval highly valuable.

Principal Harrison is the strict administrator of Carsville High. He gives Thiago a job but enforces rigid probationary rules, and he later punishes Kami, Taylor, and Julian following a parking lot brawl.