Jamie is a middle school student who uses a wheelchair following a severe car accident that claimed the lives of his parents and younger sister. He recently relocated from the countryside of Cornwall to a suburb in Long Beach to live with his adoptive aunt, uncle, and cousins. Feeling like an outsider in his new environment, he relies heavily on his natural wit to cope with his grief and deflect schoolyard bullies. He spends his free time writing observational comedy, testing his material at his uncle's diner, and working up the courage to perform in public.

Uncle Frankie is the brother of Jamie's late father and the proud owner of the oldest diner in New York. A skilled chef and an avid yo-yo champion, he maintains a highly vibrant, energetic personality that contrasts sharply with the rest of Jamie's relatives. He serves as a vital father figure, constantly encouraging Jamie to write down his stories and enter a local comedy contest.

Stevie is Jamie's eldest cousin and the most notorious tormentor at their middle school. Despite living under the same roof, he shows zero empathy for Jamie's physical disability and frequently targets him with cruel pranks, threats, and physical harassment. He belongs to the stoic "Smiley" family and remains completely immune to Jamie's attempts to use humor as a distraction.

Suzy, often referred to internally by Jamie as "Cool Girl," is a highly self-assured middle school student who wears sunglasses indoors and maintains a remarkably casual attitude. She stands out from their peers by refusing to pity Jamie or baby him because of his wheelchair. Instead, she provides an honest, grounding perspective and actively challenges him to drop his comedic defenses and speak genuinely about his feelings.

Aunt Smiley is Jamie's maternal aunt and his legal guardian following the death of his parents. She presides over a quiet, rigidly serious household where smiles are practically nonexistent, making her and her family the ultimate test audience for a budding comedian. She provides Jamie with basic shelter but lacks the warmth he craves.

Uncle Smiley is the husband of Jamie's Aunt Smiley and forms part of the adoptive family taking care of Jamie. Like his wife and children, he rarely displays any emotion or amusement, creating a tough environment for a young comedian trying to test new jokes.

Pierce is one of Jamie's two closest allies at his new school. He is an academically oriented student who treats Jamie with standard, equal respect. He makes a point to physically squat down to eye level when speaking with Jamie, ensuring he never looks down on his friend, and only offers assistance when it is strictly necessary.

Gaynor is Jamie's other best friend, easily recognizable by his eclectic style featuring tattoos and piercings. He shares a strong, sarcastic sense of humor with Jamie and provides a reliable, stigma-free friendship that helps Jamie feel ordinary during the school day.

Gilda is a fellow student who initially causes Jamie severe nervousness before they bond over a shared love of old-time comedy during a lunch period. Wearing a signature Red Sox hat, she is highly capable of fending off schoolyard bullies with her own quick wit and a compact mirror, quickly becoming an integral part of Jamie's social circle.

Mr. Burdzecki is a jolly Russian immigrant who frequently visits the boardwalk diner. Wearing a thick winter coat and an ushanka hat, he is one of the first individuals outside of Jamie's immediate family to validate his comedic talent, loudly declaring him to be a funny boy after hearing his jokes.

Shecky is a rival contestant in the youth comedy circuit. Dressed in a plaid suit with heavily combed-down hair, he relies on mean-spirited humor and openly mocks other competitors, demonstrating the darker, crueler side of using jokes to target people's vulnerabilities.

Judy is a young aspiring comedian who claims to be working with Disney. She becomes a target of Shecky's cruel insults while anxiously waiting for her turn to perform on stage.

Carly is a young girl living at the rehabilitation center where Jamie recovered after his car accident. She battles a severe illness that was expected to end her life years ago, yet she continues to fight, serving as a powerful reminder of endurance and perseverance.

Derek is a boy recovering from a severe accident at the Hope Trust center. Initially unable to walk or speak following his injuries, he demonstrates significant progress by walking and talking, providing Jamie with a tangible example of hope and healing.

Billy Crystal is a famous real-world actor and comedian who acts as one of Jamie's personal heroes. He appears as a guiding figure in Jamie's subconscious, offering much-needed validation and reminding the young boy of his natural comedic instincts when his confidence begins to waver.