Charlie is a Deaf high school sophomore from the Ohio suburbs. After living her entire life in mainstream educational settings with a faulty cochlear implant, she moves in with her father and enrolls at River Valley School for the Deaf. Having no prior knowledge of American Sign Language, she feels isolated and overwhelmed by her new environment. She is determined to find a sense of belonging and questions her lack of autonomy over her medical choices.

Austin is a confident high school sophomore and a fifth-generation Deaf person on his mother's side. Raised in an environment that treats inherited deafness as a treasured family trait, he feels deeply connected to his heritage. His usually cheerful disposition changes when his family faces unexpected news regarding his new baby sister.

February is the headmistress of River Valley School for the Deaf and a Child of Deaf Adults. She views the school as a haven for students and works to protect the Deaf community. While highly competent in her professional life, she manages deep anxiety and tends to avoid conflict in her personal affairs, especially regarding her aging mother's declining health.

Victor is Charlie's father and a software engineer. Following his recent divorce, he assumes full custody of his daughter and commits to improving their communication. He demonstrates an easygoing but dedicated parenting style, taking proactive steps to immerse Charlie in the Deaf community by enrolling her at River Valley.

Lynnette is Charlie's mother, who recently divorced Victor. She strongly advocates for Charlie to remain in mainstream schooling and insists on her using a cochlear implant, believing it provides the best opportunities. Her desire to make Charlie appear hearing-adjacent causes significant friction between them, though Lynnette views her actions as protective.

Mel is a hearing woman married to February. She is adaptable and supportive, taking in February's mother without complaint. Though she does not sign, she willingly participates in Deaf social gatherings, but she struggles with occasional jealousy regarding February's past relationships.

Beth is a fourth-generation Deaf person and Austin's mother. She holds deep pride in her Deaf heritage, treating it as a defining family trait. Expecting a new baby, she faces difficult decisions that challenge the long-held values of her strongly opinionated extended family.

Henry is Austin's hearing father and a professional sign language interpreter. His fluency in American Sign Language and marriage to Beth fully immerse him in the Deaf community. He holds a more flexible view of hearing status than his in-laws, which creates tension in the household when his new daughter is born.

Slash is a recent high school graduate and a politically minded punk musician. Formerly a goofy high school classmate of Charlie's known as Kyle, he has developed a deep concern for social issues and marginalized people. He is considerate of Charlie's communication needs and willing to break rules to protest societal wrongs.

Kayla is a Black Deaf sophomore at River Valley and Charlie's roommate. She comes from a working-class background and uses Black American Sign Language. Driven by her goal to attend Gallaudet University and become a teacher, she is highly aware of the subtle prejudices that exist even within her school community.

Eliot is Austin's roommate at River Valley. He carries a difficult past involving a traumatic car accident and a distressing experience at his mother's church. Despite a rough exterior and a reputation for drama, he forms a close bond with his roommate and gets swept up in plans to challenge authority.

Wanda is a teacher at River Valley and February's former romantic partner. She carries her own childhood trauma regarding the loss of her older brother. She remains a supportive presence in February's life, offering comfort during difficult professional times.

Swall is the superintendent overseeing River Valley School for the Deaf. He is a pragmatic administrator tasked with delivering difficult news about the school's administrative and financial future to the staff.

Gabriella is a second-generation Deaf student at River Valley. She is Austin's ex-girlfriend, carrying a sense of entitlement from her prominent standing in the school's Deaf community. She behaves coldly toward Charlie out of jealousy.

Skylar is the newest member of the Workman family. Her arrival and the subsequent medical testing to determine her hearing status spark significant ideological conflicts between her parents, her brother, and her grandparents regarding Deaf identity.

February's mother is a Deaf elder suffering from worsening dementia. She relies heavily on her daughter for care and comfort. Her transition from living independently to staying with family and eventually moving to a nursing home deeply affects February.