Finn is a recent high school graduate and talented soccer player preparing to head to college as a pre-med student. Raised primarily by his single mother, he is known for his compassion and fierce protective nature toward women. He spends his summer harboring a deep-seated love for his childhood best friend, Autumn, while feeling intense guilt over his current relationship with his girlfriend, Sylvie.

Jack is Finn’s loyal best friend since middle school and a fellow high school soccer player. As the youngest of seven sons to parents who are tired of raising children, Jack relies heavily on his friendship with Finn for stability and connection. He is highly supportive of Finn, consistently encouraging his friend to be honest about his feelings for Autumn.

Autumn is a creative, somewhat disorganized teenager and aspiring writer who has just finished a novel heavily inspired by her own life. Recently single after a bad breakup with her high school boyfriend, Autumn struggles with depression and often retreats into books for comfort. She shares a profound, lifelong bond with Finn, though they drifted apart in middle school before recently spending more time together.

Sylvie is Finn’s intelligent, self-assured, and highly organized girlfriend. Driven and ambitious, she spends the summer traveling in Europe to practice independence. Though deeply committed to Finn, Sylvie carries the lingering trauma of past harassment, which makes her demand complete honesty and security from her romantic partner.

Claire is Autumn’s mother, who has recently finalized a divorce from her husband. She prefers a perfectly decorated house and name-brand items, contrasting with her best friend Angelina’s more frugal lifestyle. Despite her focus on appearances, Claire is a highly supportive and present parent who prioritizes her daughter's well-being.

Angelina is Finn’s single mother and Claire’s next-door neighbor. She rejects consumerism in favor of secondhand goods, living a more relaxed lifestyle than her best friend. She is a warm, deeply loving mother who raises Finn primarily on her own and maintains an open, honest relationship with her son.

Angie is a high school friend of Autumn who became pregnant during her senior year. Living in her in-laws' basement with her husband and child, Angie faces the immense challenges of young parenthood. She deals with extreme exhaustion and a loss of personal identity while trying to support her growing family.

Alexis is Sylvie’s close friend and Jack’s high school girlfriend. She is part of the broader social group connected to Finn, Jack, and Sylvie, representing the typical teenage social dynamics the main characters experience.

Jamie is Autumn's former high school boyfriend. His infidelity causes their breakup shortly after graduation, an event that significantly impacts Autumn's mental health during the summer and sets her back emotionally.

Sasha is a mutual friend of Autumn and Jamie. She becomes romantically involved with Jamie, leading to the dissolution of Autumn's relationship and a lasting rift in their friend group.

John is Finn's biological father who has remained entirely absent from Finn's daily life due to his own fears of repeating his father's parenting mistakes. He attempts to compensate for his absence by providing a trust fund and sending ostentatious gifts instead of spending time with his son.

Brett is a college student who becomes Jack's roommate. He actively participates in campus events to manage his own past familial trauma, eventually forming a bond of mutual understanding with Jack as they adjust to college life together.

Dr. Singh is a psychiatrist who treats Autumn. He insists his patients participate in group therapy to facilitate their emotional recovery and personal growth, refusing to provide individual care unless this condition is met.

Brittaney is a brash but fiercely protective 21-year-old mother attending group therapy. Having endured immense personal tragedy and trauma in the foster care system, she offers blunt, practical advice and a surprisingly levelheaded perspective on life to the other group members.

Dave is Angie's young husband. He balances attending college and working while living in his parents' basement with his new family, creating significant tension and exhaustion in his marriage.