Daniel is a thirteen-year-old middle school student who serves as the backup kicker for the Erie Hills Elephants football team. He secretly battles debilitating anxiety and obsessive-compulsive habits, which he calls "zaps," forcing him into exhausting counting routines to prevent perceived disasters. Desperate to appear normal to his peers and family, he hides his struggles while writing an apocalyptic adventure novel called *The Last Kid on Earth* to cope with his feelings of isolation.

Sara is an isolated middle school student widely known by the cruel nickname "Psycho Sara" because of her selective mutism and past outbursts in class. She lives with severe mental health conditions, including depression and anxiety, which she attempts to reframe by identifying as a "Star Child" with alien DNA. Highly observant and resourceful, she reaches out to Daniel for help investigating the mysterious disappearance of her father.

John is the current boyfriend of Sara's mother. From Sara's perspective, he is a menacing figure whom she fiercely suspects of playing a sinister role in her father's abrupt disappearance. He lives in a messy house with unwashed socks and empty beer cans, presenting a rough, grizzled exterior that fuels Sara's amateur investigation.

Max is Daniel's loyal and comparatively more socially adjusted best friend. He is generally sympathetic and understanding, though Daniel actively hides the true severity of his anxiety from him for fear of altering their friendship. Max deals with his own quiet struggles, particularly regarding his emotionally distant father whose approval relies heavily on football success.

Raya is an attractive and somewhat alternative student whom Daniel desperately wants to date. She is Indian and writes poetry, showing an interest in Daniel's messy hair and his identity as a writer. To Daniel, winning her affection represents the ultimate proof that he can achieve a normal teenage life.

Steve is Daniel's sixteen-year-old older brother. Popular and confident, he has a cheerleader girlfriend and represents the standard of normal teenage success that Daniel measures himself against. Though he frequently calls Daniel mocking nicknames, he occasionally tries to help his younger brother by offering unsolicited, highly conventional advice on dating and masculinity.

Daniel's father is a busy man who works long hours and struggles to connect emotionally with his son. He attempts to bond with Daniel almost exclusively through the lens of sports and football, showing intense excitement when Daniel is promoted to the starting kicker position. He remains entirely unaware of his son's severe mental health struggles.

Daniel's mother manages the bustling Leigh household and tries to guide her children through their social challenges. She offers Daniel practical, if sometimes superficial, advice on how to behave around girls, encouraging him to dance and be polite so he won't be seen as the guy hiding in the corner.

Taj is a burly, aggressive football player who acts as a primary tormentor for Daniel. He embodies the loud, obnoxious confidence that Daniel lacks, strutting around school and easily securing Raya as his date to the dance.

Emma is Daniel's nine-year-old sister. She maintains a sweet, uncomplicated relationship with Daniel, who frequently reads stories to her. She provides him with a safe family connection devoid of the pressures he feels from his parents and older brother.

Clara is Raya's friend who dresses elaborately, often compared to a Barbie doll, in her attempts to get noticed by boys at school. She has a clear crush on Max and participates in the superficial social games of middle school dating.

Miss Lecky is the teaching assistant specifically assigned to help Sara at school. Despite her job title, she is largely indifferent to Sara's actual needs, often ignoring her to text on her phone or physically grabbing her in ways that only escalate Sara's distress.

Mr. Keats is Daniel's geography teacher. He represents the general apathy of the school staff, frequently creating work periods so he can sit behind his desk and read the newspaper rather than actively teaching his students.

Kevin is the original starting kicker for the Erie Hills Elephants football team. When he gets injured, Daniel takes his spot. Upon recovering, Kevin is highly resentful and confronts Daniel, accusing him of actively stealing his position on the team.