Tom is a quiet, overweight seventh-grader who prefers to remain unnoticed at St. Catherine's Catholic school. He has a rich imaginary life where he rescues his crush, Courtney, using uniquely small superpowers. Highly empathetic, he struggles to articulate his feelings and often experiences physical distress, like stomach aches, during stressful situations.

Jessica is a burn survivor who relocates from Boston to receive specialized skin graft treatments at a nearby hospital. She keeps her head down in class and speaks with a faint voice. Despite the painful injuries she endures and the cruelty of her peers, she proves to be highly intelligent and observant.

Jeff is Tom's primary friend and is known for his unpredictable antics and chewed fingernails. He harbors deep anger stemming from his parents' divorce, living with his overworked mother while resenting his absent father. He reacts to the new student with open hostility, differing entirely from Tom's quiet empathy.

Courtney is a popular and smart student at St. Catherine's school. She features heavily in Tom's daydreams as a damsel in distress, but in reality, she is passionate and engaged in her education. She possesses a strong sense of fairness and pays attention to how others treat the new student.

Tom's parents provide a stable, supportive home environment. They are affectionate and actively try to help Tom break out of his shell. They gently push him to participate in school activities and engage with his peers.

Jessica's parents are devoted caregivers who appear sad and withdrawn as they deal with the aftermath of a severe car accident. They temporarily move their family to a local condo so their daughter can receive specialized medical treatments.

Jeff's divorced parents are largely absent from his daily life. Mrs. Hicks works long hours as a hospital nurse, while Mr. Hicks lives in the city with his new girlfriend and resents paying for his son's Catholic school tuition.

Mrs. Tracy is an enthusiastic, well-liked seventh-grade teacher at St. Catherine's. She attempts to treat all her students equally and hopes the class will be welcoming. She struggles to effectively manage the students' underlying prejudice toward physical differences.

Rich is a jokester in Tom's seventh-grade class. He easily falls in line behind louder personalities, participating in insensitive speculation and spreading malicious rumors about the new student's injuries.

Uncle Chuck is Jeff's relative who supposedly owns a restored classic 1960s Shelby Cobra. He serves as a bargaining chip for Jeff to maintain his friendships and impress his classmates.

Kayla is a student in Mrs. Tracy's class. She displays open insensitivity toward the new student and suggests telling the teacher that the class feels frightened by the recent changes.