The young protagonist lives in a suburban neighborhood directly across the street from his closest companion, Jamie. He possesses a cautious nature and thinks carefully about the consequences of his actions. He frequently worries about getting into trouble or facing physical danger. He lives with his parents and is the youngest of three siblings.

Jamie is a daring, adventurous boy who lives across the street from the narrator. He loves securing the attention of others and frequently goofs off. He acts as if he is invincible and regularly pushes boundaries, whether he is sneaking apples from a guarded farm or hitchhiking home during a storm. He also serves as a remarkably patient and kind older brother to his younger sister.

Heather is a young neighborhood girl who spends a significant amount of time with the narrator and Jamie. She approaches unpredictable situations with a strong sense of caution. She quickly warns her friends when they engage in risky behavior.

Martha is Jamie's four-year-old sister. She maintains a pudgy baby appearance and frequently tags along with her older brother. Jamie genuinely enjoys her company and purposefully includes her in his daily adventures with the narrator.

Mrs. Houser is a notoriously grumpy neighbor who lives across the street from the narrator. She fiercely guards her property and frequently yells at local children if they accidentally step over her boundary line. She shocks the neighborhood kids by offering to pay them money to scrape Japanese beetles off her plants.

Mrs. Mullins is an older woman in the neighborhood with a large, quiet garden. Many local children find her unusual because she dislikes loud noise that frightens her birds. She actually possesses a gentle demeanor and extends a welcoming attitude toward the narrator.

The narrator's mother is an active participant in the local neighborhood community. She is friendly with the other neighbors, including the quiet Mrs. Mullins. She maintains a relaxed household that allows her son and Jamie to freely move back and forth between their houses.

The narrator's father lives in the neighborhood and helps raise his youngest son. He provides a quiet, reliable presence in the household.

Jamie's mother lives across the street from the narrator's family. She raises three children and frequently hosts the narrator in her home. Like the narrator's mother, she treats the neighborhood boys like family.

Jamie's father lives with his family across the street from the narrator. He helps raise Jamie, Martha, and the family's new baby.

The farmer owns an apple orchard on a farm surrounded by the city. Local neighborhood rumors claim he ruthlessly guards his private property with a shotgun.