Kidd is a teenager struggling with severe trauma and depression after the violent deaths of his parents. He runs away from Horizons, a group home for troubled youth, to find work doing maintenance at a beachside campground. Deeply lonely and lacking self-esteem, he records his thoughts and personal philosophies in a journal as he tries to build a new life.

Devon is a fellow resident at the Horizons group home who attaches himself to Kidd. Harboring intense resentment toward wealthy people and societal privileges, he acts out through risky behavior and violence. He possesses a dangerous unpredictability and constantly pressures Kidd to revert to destructive habits, viewing their friendship as an exclusive alliance against the rest of the world.

Red manages a beachside campground where he hires Kidd to do maintenance work. A surfer in his thirties, he functions as a surrogate father figure and mentor to Kidd, offering life advice and steady employment. He is honest about his ongoing recovery from alcohol addiction and the grief of losing his teenage son, choosing to model how to carry emotional burdens while living a good life.

Olivia is a wealthy teenager spending her summer at the beach campsites. She constantly wears a ski cap pulled low to cover a rare, enlarging skin condition on her scalp and face, which makes her highly self-conscious and prone to depression. Despite her affluent background—which includes famous piano instructors and expensive travel—she shares a deep emotional vulnerability with Kidd that draws them together.

Maria is a counselor at Horizons, the group home where Kidd is placed following his parents' deaths. She genuinely cares about Kidd's progress and encourages him to separate himself from negative influences.

Peanut is a scruffy, quiet stray dog that lives at the campground. He proves to be an attentive, loyal companion to both Red and Kidd.

Kidd's mother is a victim of severe domestic violence who struggles with alcohol use. She deeply loves her son, calling him her "lucky charm," and attempts to make a desperate choice to protect him from his abusive father.

Kidd's father is a violent man who subjects his wife and son to physical abuse and terror. His actions leave deep psychological scars on Kidd, driving the boy to change his own name to distance himself from his father's legacy.

Jessica is a zookeeper who takes Red and Kidd behind the scenes during a visit. She offers Kidd encouragement and suggests he apply for a summer internship working with animals.

Bill is Red's AA sponsor. He provides essential support to Red in his ongoing struggle with addiction.

Jasmine is a friend of Olivia's who spends time at the beach and the campground. She observes Kidd and Olivia's developing connection.