Jake is a perceptive, optimistic elementary school student with a good sense of humor. He enjoys school and reading but struggles with a tendency to attract bullies because of his size, lack of an older sibling, and reluctance to tattle. He is highly sensitive to the social dynamics of his classroom and deeply values the approval of his peers.

Link is a new student who is tall for his age, with long arms and large hands. He projects a tough exterior and quickly targets Jake for intimidation, using physical tactics and psychological manipulation to earn the laughter of his peers. Despite his aggressive behavior, he hides personal vulnerabilities and a deep need for social approval.

Willie is Jake's closest friend. He is smaller than average, mild-mannered, and prefers to mind his own business. Because he stays out of trouble and does not react strongly to intimidation, he avoids being targeted by the school bullies.

Abby is Jake's younger sister, a second-grader when Jake is in fourth grade. She is surprisingly emotionally intelligent for her age, recognizing that getting angry only makes her feel mean. She enjoys typical young children's television shows but offers practical advice when her brother struggles with school conflicts.

Mrs. Brattle is an encouraging second-grade teacher known as the best educator at Despres Elementary School. She creates an engaging classroom environment filled with interesting materials. However, she frequently misses the subtle social cues and silent conflicts happening among her young students.

Pete is one of Jake's friends in the fourth grade. He is observant and playful, testing his theories about their teacher's limited wardrobe by secretly marking his pants with a tiny spot of ink.

Mrs. Karp is the principal of Despres Elementary School. She is stern but handles disciplinary issues with a gentle tone, making sure students understand the school rules regarding physical fighting.

Mr. Thompson is a fourth-grade teacher at Despres Elementary. He is well-liked by Jake but amuses his students by rotating only two pairs of similar tan pants throughout the school week.

Mrs. Steele is a demanding fourth-grade teacher at Despres Elementary. Willie does not enjoy her class because she assigns a heavy amount of homework.

Linda is Link's younger sister and is in the same class as Abby Drake. She mirrors the bullying behavior present in her household by acting aggressively toward her own classmates.