Grayson is a solitary sixth-grader living in Chicago with her aunt and uncle after the death of her parents. Though perceived by the world as a boy, Grayson knows she is a girl, a truth she keeps hidden out of fear of rejection. She expresses herself privately through drawing and imagining herself in dresses, while slowly finding the courage to make friends and participate in school activities.

Evan is Grayson's uncle and the brother of her late father. He provides for the family but often feels disconnected from his brother's memory. He shows a genuine desire to support his niece and understand her needs, contrasting with his wife's socially anxious approach to parenting.

Sally is Evan's wife and Grayson's aunt. She cares for Grayson but worries deeply about social conformity, bullying, and outside perceptions. Her attempts to protect Grayson often manifest as pressure to hide any feminine traits, creating tension and emotional distance in their household.

Affectionately known as Finn, he is Grayson's favorite teacher and the school theater director. He fosters a warm classroom environment and pays close attention to his students' emotional states. He notices Grayson's isolation and encourages her interest in the school play, acting as a crucial mentor figure.

Paige is an expressive eighth-grader known for getting lead roles in school productions. She dresses in brightly colored, unique layers that reflect her self-assurance. She acts as a protective older friend to Grayson in the theater environment, helping her feel accepted.

Amelia is a new student at Porter who recently moved to Chicago from Boston following her parents' divorce. She initially reaches out to Grayson, and the two bond over feeling like outsiders and visiting thrift stores. However, her desire to fit in with more popular girls eventually strains their connection.

Jack is Grayson's older cousin. He frequently mocks Grayson for her quiet demeanor and perceived differences. His teasing creates an unsafe environment for Grayson at home and heavily influences his parents' restrictive approach to raising her.

Brett is Grayson's second-grade cousin. Unlike his older brother, Brett views Grayson with innocent affection and does not understand the social pressures surrounding gender roles or school plays.

Ryan is a vocal classmate who consistently targets Grayson for being different. He leads the teasing in the hallways and classroom, representing the social hostility Grayson fears from her peers.

Sebastian initially follows Ryan's lead in bothering Grayson. Over time, his behavior shifts, and he shows a more thoughtful side, particularly during science class interactions and school discussions.

Lila is a quiet but socially powerful girl in Grayson's grade. She commands the attention of the other girls and eventually draws Amelia away from Grayson, establishing a social hierarchy that excludes those who are different.

Meagan is a friendly classmate who participates in the school play. She quietly offers Grayson support and inclusion in social activities without drawing unnecessary attention to the situation.

Marla is Paige's mother. She volunteers to help with the school play's wardrobe. Like her daughter, she is warm, accepting, and actively works to provide a safe space for Grayson.

Lindy is Grayson's late mother, an artist who died in a car accident when Grayson was four. She leaves behind letters and paintings that offer Grayson crucial emotional grounding and a sense of belonging.

Ms. Landen assists Mr. Finnegan with the school play. She helps manage the students during rehearsals and supports the casting decisions that allow students to explore their identities.

Tyler is Ryan's older brother. He joins his brother in targeting Grayson outside of class, using his physical size to intimidate younger students.