Tod is a large, eighth-grade student known around his middle school as a hardened bully and thief. He lives in a cold, cramped home with his mother and stepfather, facing constant hunger and financial struggles. Despite his intimidating exterior, he possesses high intelligence, earns honor roll grades, and is highly observant of his environment. He expresses his frustration with his circumstances through cynical and dark journal entries assigned by his guidance counselor.

Mrs. Woodrow is a straightforward guidance counselor who intervenes to keep Tod out of juvenile hall. She mandates that he write in a journal every day as an alternative to picking up trash with his friends. She reads his entries and leaves direct, non-judgmental notes in the margins to challenge his perspective and behavior.

Luz is an artistic student whom Tod describes as the "spooky goth girl." She is highly talented, creating an elaborate sphinx statue out of car parts that is displayed at the school's entrance. She receives free lunch and writes a school play about immigrants, representing an unconventional but confident presence at the school.

Rex is one of Tod's closest associates, living in poverty in the same neighborhood. He is moody and prone to violent outbursts or chaotic behavior, such as breaking into cars. Despite his bitter attitude, he possesses a surprising familiarity with biblical scripture, allowing him to quote verses verbatim to intimidate others.

Rob is an outwardly friendly student who comes from a middle-class background, making him wealthier than his peers. He chooses to socialize with Tod, Rex, and Bernie because he enjoys stealing and finds their rebellious behavior appealing. His comparative wealth creates tension, as Tod resents Rob's unhappiness despite his stable home life.

Bernie is Tod's oldest friend. Scrawny and living in deep poverty, he frequently misses school to care for his ill mother. He depends on Tod for protection and help with his homework, serving as a vulnerable counterpart to the group's aggressive exterior.

Tod's mother works long hours as a tailor for a local dry cleaner to support her family. She is constantly overwhelmed by financial strain and relies on public transportation. She forces Tod to help with her mending work and keeps his earnings to pay for essential household expenses.

Dick is Tod's stepfather who works in landscaping. He is demanding and complains about Tod watching television in the cramped house. His strict presence contributes to the tense atmosphere that makes Tod prefer avoiding his home.

Mr. Harmon is Tod's easygoing English teacher who keeps famous literary quotes posted by his door. He recognizes Tod's intelligence despite the boy's attempts to hide it during class discussions. He shows favoritism to certain students involved in the audiovisual club, ignoring their cruel behavior toward others.

Greg is the head of the school's video club and a favored student in Mr. Harmon's English class. He actively cyberbullies Tod by recording humiliating videos of him at school and posting them online for other students to watch.

Karen is a popular, wealthy student at the school. She is outwardly mean to outcasts during school events and uses her high social status to extort money from other affluent children purely for sport.

Mr. Carnegie is the school principal. He views Tod strictly as a delinquent and frequently calls his home to discuss his violent outbursts, failing to look past Tod's aggressive reputation or understand his home life.

Ricardo is a student whom Tod regularly targets for bullying. Tod knocks him down and breaks his glasses in the incident that kicks off Tod's ongoing narrative, though Tod surprisingly helps him up afterward.

Mrs. Lent is the school librarian who manages the reading room. Though she has a reputation for being strict, she is one of the few adults in the building who treats Tod with genuine respect and allows him to spend time reading.

Mrs. Cornell is the head of the English department. She intentionally excludes Tod from the school spelling bee to prevent him from representing the school on television, demonstrating the administration's classist attitudes.

Mr. Phister is the school art teacher. He is openly disdainful of Tod and gives him poor grades, refusing to recognize any effort Tod puts into his assignments because he views him as unworthy of expensive art supplies.

Stuart is a blind student who works as Tod's partner in science class. He interacts casually with Tod and is quick to tease him about having a potential crush on Luz after she drops off an audition flyer.

Karl is a disruptive student originally cast as the Criminal in Luz's play about 1899 immigrants. He mocks Tod in the lunchroom while enjoying his temporary popularity from being in the cast.