Eric is a 13-year-old boy who recently moved from Ohio to Bellport, Long Island, with his mother and younger brother. He misses his father, who abandoned the family due to mental illness, and often seeks emotional relief by playing the guitar and listening to classic rock CDs. Lonely and hoping to fit into his new environment, Eric initially welcomes the friendship of a charismatic local boy but quickly begins to question the school's harsh social dynamics.

Griffin is a handsome, charismatic middle school student who serves as the leader of a prominent local clique. He presents a polite, helpful demeanor to adults, easily charming parents and teachers with his good manners. Behind this friendly exterior, he exerts control over his peers through intimidation and casual cruelty, collecting stolen items from his victims that he refers to as 'souvenirs.'

David is a frail, anxious boy with a pale, freckled face and a high-pitched voice. He is the frequent target of Griffin's clique, subjected to physical shoves and humiliating pranks. Desperate for peer acceptance, he refuses to report his abusers to teachers and attempts to earn a place within the very group that torments him.

Mary is a middle school student with a natural beauty who initially associates closely with Griffin's group. She quickly identifies Eric as a person of interest when he arrives in town. Unlike her peers, she harbors reservations about the cruelty of the school's social hierarchy and the cyberbullying planned by her female classmates.

Cody is a scrawny boy with a beaked nose and buckteeth who serves as Griffin's close friend and physical enforcer. Having learned martial arts from a local resident, he acts as the muscle for the clique's intimidation tactics. He is highly sensitive about his appearance and fiercely loyal to his group's social order.

Eric's mother recently relocated her two sons to her hometown in New York to start over after her husband's departure. She is optimistic about the move and easily won over by polite, well-mannered youths like Griffin.

Eric's absent father suffers from schizophrenia, a condition that caused him to stop working and eventually abandon his family. His unpredictable behavior in the past forced the family's current relocation, leaving a lasting emotional impact on his older son.

Rudy is Eric's younger brother who joins the family in their move from Ohio. He keeps his savings in a baseball-shaped bank in his bedroom.

Griffin's father is a large, imposing man who struggles with alcohol use. He creates a tense, unsupervised home environment for his son and uses physical discipline to maintain control in his household.

Mrs. Rosen is an older, wealthy woman who works as a school lunch aide and occasionally hires local students for chores. She recently lost her dog, Daisy, a fact that draws superficial sympathy from certain students but genuine interest from others.

Mr. Floyd is the school counselor at Belmont Central Middle School. He actively tries to intervene in the school's social problems by identifying verbal, physical, and indirect harassment tactics for the student body.

Mr. Scofield is an English teacher who uses historical events and psychological studies to challenge his students. He teaches his class about the Milgram Experiment to emphasize the importance of independent thought over blind obedience.

Chantel is a female student at Belmont Central Middle School. She draws the ire of a popular group of girls, making her the focus of a planned digital harassment campaign involving manipulated photographs.

Alexis is the leader of a popular group of girls at the middle school. She uses digital platforms and manipulated images to mock and isolate other students she dislikes.

Officer Goldsworthy handles security and conflict resolution at the school. He monitors the social dynamics of the student body and tracks minor crimes in the surrounding community.

Drew P. is a member of Griffin's social circle. He justifies the group's cruel behavior by comparing middle school dynamics to scientific theories of natural selection.

Pat is a minor member of the local middle school social scene who associates with Cody and enjoys playing basketball.

Hakeem is a middle school student at Belmont Central who associates with the peripheral members of Griffin's extended peer group.

Sinjay is a student at Belmont Central Middle School who forms part of the general background of boys observing the local social hierarchy.

Will is a classmate at Belmont Central Middle School who spends time with the other boys outside the immediate influence of the school's primary cliques.