Jerome is a 12-year-old Black boy from a working-class Chicago neighborhood who tries to remain invisible to avoid trouble. Before his death, he is an ordinary seventh-grader who worries about his family and dreams of playing professional basketball or going to college. As a newly deceased ghost, he wanders the city, observing his grieving family and trying to understand the circumstances of his death.

Based on the historical figure whose 1955 murder mobilized the civil rights movement, Emmett appears as an experienced ghost boy. He serves as a spirit guide for Jerome, helping the newly deceased boy understand his afterlife. He understands the profound grief of the living and the historical burden placed on Black children.

Sarah is the sheltered 12-year-old daughter of the police officer involved in Jerome's shooting. She lives a comfortable, middle-class life in a predominantly White neighborhood, completely insulated from the dangers Jerome faced daily. Her sudden ability to see Jerome forces her to confront harsh realities outside her previous experience.

Carlos is a lonely, working-class transfer student who struggles to fit into his new Chicago school. Recognizing a fellow outcast, Jerome steps up to be his lunch buddy. Carlos protects himself and his new friend, bringing a toy gun to school because he is unwilling to silently endure the abuse of local bullies.

Officer Moore is the Chicago police officer who shoots Jerome while responding to a 911 dispatch. He claims he acted in fear for his life, describing the small 12-year-old as a large, threatening figure. His actions devastate the Rogers family and throw his own household into turmoil.

The Southern-born matriarch of the Rogers family holds deep folk beliefs and a profound spiritual sensitivity. She is a protective presence who required Jerome to list "three good things" every morning before he faced the dangers of the neighborhood. Her intuition keeps her partially tethered to Jerome after his death.

Jerome's younger sister is a well-behaved girl who uses reading as an escape from the harshness of their environment. She understands the strict rules Black children must follow to stay safe and serves as a quiet observer of the risks her brother takes.

A ghostly figure based on the real-life teenager killed in 2012. He wears a distinctive hoodie and stands alongside other murdered boys, representing the vast historical scale of the tragedy Jerome has joined.

Three aggressive middle school bullies who regularly torment Jerome. They force him to hide in the bathroom during lunch to avoid beatings, creating the stressful environment that pushes Jerome to seek an alliance with Carlos.

Jerome's hardworking parents constantly worry about their children's safety and hold strict rules designed to keep them alive. Following Jerome's death, they are consumed by profound grief, anger, and the struggle to secure justice for their son.

Carlos's father, who relocated his family from San Antonio to Chicago. He maintains their cultural traditions and provides a supportive presence for his son as Carlos adjusts to the dangerous new city.