Lincoln is a 12-year-old Hispanic American student and basketball player. He has recently moved with his mother from San Francisco's urban Mission District to the affluent, mostly white suburb of Sycamore. Experiencing intense culture shock, Lincoln feels out of place at Columbus Junior High, where he is one of the only students of color on the basketball team. He frequently looks at a picture of a camel driver in his geography book, feeling a connection to the man's anonymity.

Tony is a Hispanic American basketball player attending Franklin Junior High in the Mission District. He is Lincoln's lifelong best friend. He adopts a tough attitude common in his urban neighborhood but harbors genuine anxiety about losing his connection to his best friend. He shares a recurring series of sports bets with Lincoln, which helps maintain their bond despite the physical distance.

Coach Yesutis is the angry, abrasive basketball coach at Columbus Junior High. A white man who grew up in the area and played for Columbus in the 1970s, he maintains a harsh coaching style that involves yelling, picking favorites, and calling his players names. He specifically targets Lincoln with undue criticism, lacking sympathy for injuries and creating a hostile environment on the court.

Monica is a Hispanic American student who attends Columbus Junior High. She previously went to Franklin in the Mission District, connecting with Lincoln over their shared heritage and mutual love for basketball. She practices aikido and journals in the library, providing Lincoln with a familiar and comforting presence in his new, unfamiliar school.

James is a white student who lives across the street from Lincoln in Sycamore. He plays as a second-stringer on the Columbus Junior High basketball team. Despite Lincoln's early assumptions about his affluent suburban peers, James proves to be down-to-earth and welcoming. He nicknames himself "Snake" and regularly invites Lincoln to play video games and eat with his family.

Roy is Mrs. Mendoza's new boyfriend. He is a white man who drives a baby-blue BMW and spends significant time at the Mendoza household. Initially, Lincoln views him as a typical privileged suburbanite and resents his presence. However, Roy has a working-class background and a surprising history with the Mission District that challenges Lincoln's assumptions.

Mrs. Mendoza is Lincoln's mother and a successful graphic artist. She moves her family to the Sycamore suburbs after a break-in at their Mission District home. She adapts well to her new lifestyle, driving a nice car and dating a new boyfriend, while still keeping her cultural identity by cooking traditional Mexican American meals for her son.

Mr. Kaehler is James's father. He works as a surveyor, which surprises Lincoln, who expected all the wealthy Sycamore residents to work as doctors or lawyers. He is welcoming to Lincoln and discusses basketball with him.

Mrs. Kaehler is James's mother. She is a warm and kind woman who invites Lincoln to share food and watch football with her family, helping him feel more comfortable in Sycamore.

Mrs. Contreras is Tony's mother. She still lives in the Mission District and maintains a warm, affectionate household. When Lincoln visits his old neighborhood, she immediately showers him with love and hugs.

Vicky is Lincoln's first girlfriend from his time at Franklin Junior High. Though she does not actively appear in the current narrative, Lincoln's memory of her, connected to a shared geography book found in her locker, represents the comfort of his past life.

Durkins is a student and basketball player at Columbus Junior High. When Lincoln is benched, Durkins questions Lincoln's loyalty to the team by focusing on Lincoln's use of pronouns regarding their upcoming game.

Bukowski is a vocal and aggressive basketball player for Columbus Junior High. He confronts Lincoln in the hallway about his attitude toward their team's chances of winning, leading to a tense standoff before the game.

Mr. Ramos is the basketball coach for Franklin Junior High in the Mission District. He represents the supportive community Lincoln misses and warmly invites Lincoln's family to join the Franklin team for pizza after the game.

Flaco is Lincoln's pet dog. He joins Lincoln outside in his new neighborhood, providing a small sense of companionship in the unfamiliar Sycamore environment.