Isabella, who goes by Izzy, is an 11-year-old biracial girl adjusting to a strict custody arrangement between her wealthy Black father and working-class white mother. She is a dedicated and talented pianist preparing for a high-stakes recital playing Muzio Clementi's Sonatina in C Major. Feeling split down the middle by her parents' vastly different lifestyles and impending new marriages, she searches for a stable sense of identity. She is perceptive, creatively gifted, and highly attuned to the sounds and rhythms of the world around her.

Isaiah is Izzy's father, a highly respected and affluent corporate lawyer specializing in investment banking in Cincinnati. He operates with a formal, straight-laced demeanor, carefully managing his public appearance because he is acutely aware of how Black men are judged in modern America. He lives in an elegant home with a Steinway grand piano and drives a Mercedes. Though he maintains a rigid schedule and often clashes with his ex-wife, his actions are driven by a fierce, protective love for his daughter.

Nicole is Izzy's white mother, a laidback and free-spirited woman who works as a server at a Waffle House. She provides a clear alternative to her ex-husband's wealth, living in a cluttered home filled with mismatched furniture and serving casual meals like hot dogs. She wears pastel t-shirts with quirky sayings and rainbow leggings. Despite her relaxed approach to schedules, she is a fiercely protective mother who refuses to let anyone marginalize her relationship with her daughter.

Darren is Anastasia's teenage son and a high school junior. He is an honor roll student and a skilled athlete who spends his weekends volunteering at a local homeless shelter. Already attracting attention from top-tier colleges like Harvard, he serves as a supportive older brother figure for Izzy during her custody weeks at her father's house. He is mature, grounded, and consistently encourages Izzy's musical talents.

Imani is a young Black girl who has been best friends with Izzy since the third grade. She lives in a home decorated with African art and maintains a deep, vocal pride in her heritage. In the classroom, she is unafraid to speak up against ignorance and bigotry, setting a strong example for Izzy. Her direct experiences with racial insensitivity heavily influence Izzy's growing awareness of how society views people of color.

Anastasia is a wealthy interior decorator and a widow who lives with Isaiah. She maintains a sophisticated presence that matches Isaiah's high-class lifestyle. She also plays the piano and introduces Izzy to a collection of vintage blues and boogie-woogie sheet music, expanding the young girl's musical horizons beyond classical pieces. She makes concerted efforts to include Izzy in her life as she prepares to marry Isaiah.

John Mark is Nicole's boyfriend, a working-class man who drives a pick-up truck and has multiple tattoos. Despite his rough exterior and his upbringing in a deeply prejudiced family, he consciously rejected those bigoted views long ago. He treats Nicole with sincere devotion and makes a genuine effort to connect with Izzy, ensuring she feels comfortable as their family dynamic shifts.

Mr. Kazilly is an English and history teacher at Izzy's school. He intentionally introduces complex, real-world issues to his sixth-grade students, connecting historical civil rights movements to modern activism. He encourages his students to think critically about identity, society, and their personal responsibilities to one another.

Logan is a white classmate of Izzy and Imani. During a serious lesson about the history of racism in America, he makes a rude, dismissive comment minimizing the horrors of lynching. His casual bigotry sparks a confrontation in the classroom and serves as Izzy's first direct exposure to the casual cruelty of her peers.

Madame Rubenstein is an accomplished instructor from the Music Conservatory at the University of Cincinnati. She oversees Izzy's rigorous training for a major classical recital, demanding precision, intricate fingering, and perfect timing. Her disciplined approach contrasts sharply with the lively, syncopated blues music Izzy discovers on her own.