Ravi is a confident, recently immigrated fifth grader from Bangalore, India, who has just moved to Hamilton, New Jersey. Accustomed to being a top student and star athlete at his strict former school, he expects to quickly impress his teachers and classmates at Albert Einstein Elementary. He dresses formally, respects adult authority, and assumes his high intelligence will naturally translate to popularity in America.

Joe is a quiet, physically large fifth grader who has lived in Hamilton his entire life. He has Auditory Processing Disorder, a condition making it difficult for him to filter out background noise. Teachers and peers often mistake his lack of participation for a lack of intelligence. He prefers to keep a low profile, especially since his two best friends recently moved away.

Dillon is the most popular boy in the fifth grade at Albert Einstein Elementary. He is wealthy, physically coordinated, and acts as a foil to both Joe and Ravi. He craves attention and uses his social standing to continuously torment students he views as weaker.

Mrs. Beam is the short, round fifth-grade teacher at Albert Einstein Elementary with highly expressive eyebrows. She tries to manage her classroom effectively but lacks familiarity with Joe's auditory disorder and Ravi's cultural background, inadvertently causing stress for both boys.

Miss Frost is the resource room teacher at Albert Einstein Elementary. She is patient, empathetic, and one of the few educators who truly understands Joe's auditory condition. She provides a safe space for struggling students and actively discourages them from making negative assumptions about one another.

Mr. Barnes is Joe's former fourth-grade teacher. He is known for shaving his head, wearing real bow ties in a specific pattern, and being highly skilled at Hacky Sack. He serves as an important male role model for Joe and openly disapproves of Dillon's bullying.

Amma is Ravi's mother. She is deeply affectionate and frequently demonstrates her love for her only son by cooking his favorite traditional Indian meals. She worries about Ravi's transition to his new school and often clashes with her mother-in-law over household matters.

Perimma is Ravi's paternal grandmother, who moved from India to New Jersey with the family. She is highly traditional, critical of American culture, and holds very high expectations for Ravi's academic success. She often complains about her daughter-in-law's cooking and household management.

Joe's Mom is a former nurse who recently took a job as a lunch monitor at Albert Einstein Elementary after being laid off. She is loving and highly involved in Joe's life, though she often fails to realize when her affectionate actions embarrass him in front of his peers.

Joe's Dad is a truck driver who spends long hours on the road to support his family. He bonds with Joe over baseball but struggles to understand Joe's Auditory Processing Disorder, often dismissing it and urging his son to simply toughen up against bullies.

Appa is Ravi's father, whose IT job prompted the family's relocation from Bangalore to New Jersey. He is supportive of his son and tries to maintain peace in the household between his wife and his mother.

Perippa is Ravi's grandfather. He is generally quiet in their new American home but possesses a strong sense of family pride and history, having previously managed a tea plantation in India.

Lucy is a fifth-grade student in Mrs. Beam's class. She used to be friends with Joe in nursery school but now aligns herself with the popular crowd, frequently laughing at Dillon's disruptive antics and participating in his mockery.

Emily is a student in Mrs. Beam's class. During an early assignment, she giggles at Ravi's accent and struggles to understand him, making it difficult for them to find commonalities.

Celena is a responsible student in Mrs. Beam's class. She attempts to be helpful by bringing Ravi his things after he gets hurt in gym class, inadvertently becoming involved in a classroom mystery later on.

Mia is the Sylvester family dog. She is easily frightened by thunderstorms but provides Joe with quiet, unconditional companionship when he is upset with his parents or struggling at school.