Alfonso is a junior high student who is highly conscious of his physical appearance, going so far as to do daily sit-ups and attempt to straighten his own teeth. He often blows his problems out of proportion, displaying a childlike tendency to view minor setbacks as catastrophic. Despite his insecurities, he is determined to impress a neighborhood girl and handle the awkwardness of early dating.

Jesse is a young boy who loves baseball and desires to project an image of physical strength. When he fails to make the formal Little League team, he joins a makeshift neighborhood team at Hobo Park. He stoically plays catcher without protective gear, demonstrating his uncomplaining dedication to the sport despite his lack of resources.

Hector is a quiet, thoughtful nine-year-old boy who spends his summers with his grandparents. He finds himself placed in the uncomfortable position of acting as a cultural and linguistic bridge for his family. Though he lacks adult knowledge, he dutifully tries to fulfill his grandfather's requests to investigate real estate out of familial loyalty.

Veronica is a young girl struggling with societal beauty standards that make her covet a blond, blue-eyed Barbie over her dark-haired imitation doll. She receives her dream toy for Christmas, leading to conflict with her friend. A mishap forces her to reevaluate her material desires and accept the things she already possesses.

Fausto is a young boy who desperately wants an instrument but knows his family cannot afford one. His strong desire leads him to execute a deceptive scheme to earn reward money for a supposedly lost dog. His powerful conscience ultimately prevents him from keeping his ill-gotten gains, demonstrating his strong underlying morals.

Victor is an awkward middle schooler trying desperately to impress a girl named Teresa. He adopts ridiculous strategies, like scowling to look handsome and pretending to speak French, which backfire and cause him intense embarrassment. He learns the hard way about the pitfalls of maintaining a false public image.

Yollie is a smart eighth-grade student who shares a loving, playful relationship with her mother. She feels the sting of her family's poverty acutely, especially when her mother's cost-saving measure of dyeing an old dress results in a humiliating disaster at a school dance. She eventually learns to look past material embarrassments.

Mrs. Moreno is Yollie's hardworking, entertaining mother who immigrated from Mexico with almost nothing. She pushes her daughter to excel academically so she can escape poverty. Though her creative attempts to save money sometimes backfire, her actions are always rooted in deep love and a desire to provide for her child.

Gilbert is a fifth-grader who hopes to defend himself against a local bully by learning martial arts. His naive belief that real life works like the movies is shattered when actual karate classes prove to be tedious, unglamorous, and ineffective for quick self-defense. He ultimately becomes disillusioned with romanticized action tropes.

Manuel is a student who craves the spotlight and volunteers to lip-sync to the song "La Bamba" at a school talent show. When a technical malfunction forces him into an embarrassing situation on stage, he quickly learns to lean into the comedy of the moment and embraces the unexpected positive attention from his peers.

Lupe is a highly intelligent, straight-A student who lacks physical strength. Determined to excel at a physical activity, she applies intense discipline and rigorous training to become a marbles champion. Her methodical approach to the game demonstrates remarkable focus, while her interactions with opponents show genuine good sportsmanship.

Maria is a high school sophomore who feels constrained by her family's working-class status and resents their traditional vacations. After successfully demanding to stay home alone, the isolation forces her to confront her own selfishness. She worries endlessly about her family's safety, which deepens her appreciation for them.

Ernie is Alfonso's older brother who frequently argues with him over matters of jealousy and pride. Despite his initial refusal to loan his brother a bicycle for a date, he pays close attention to Alfonso's situation and ultimately proves to be a supportive sibling.

Sandra is a neighborhood girl who catches Alfonso's attention. She is receptive to his awkward advances and happily agrees to go bike riding with him, showing an easygoing nature that relieves Alfonso's intense anxiety.

Luis is Hector's grandfather who holds unrealistic dreams of striking it rich in the local real estate market. Because he is less comfortable with American business practices, he mistakenly assumes his nine-year-old grandson can expertly negotiate complex property inquiries over the phone.

Martha is Veronica's friend who enjoys playing pretend with their dolls. She is fiercely accused of trying to steal Veronica's new doll, but later helps Veronica search for the doll's missing head despite the insult.

Helen is a wealthy, kindly woman who showers Fausto with gratitude and pity when he returns her dog. She insists on feeding him and praises his character, inadvertently making him feel deeply guilty for his deception.

Teresa is a seventh-grade student who is the object of Victor's intense affections. She is friendly toward him and is easily impressed by his fabricated French-speaking abilities, eventually asking him for tutoring help.

Mr. Bueller is a French teacher who quickly realizes that Victor is faking his knowledge of the language. Remembering his own foolish attempts to impress girls in his youth, he sympathetically keeps Victor's secret to spare the boy's feelings.

Pete the Heat is the school bully who easily defeats Gilbert in physical altercations. He serves as the primary catalyst for Gilbert's desperate but ultimately flawed desire to learn martial arts.

Maria's father is a hardworking man who grew up enduring significant hardships in Chihuahua, Mexico. He demands respect and struggles to understand his daughter's teenage rebellion, though he clearly cares deeply for his family.