Biz is a 16-year-old high school junior living in Wollongong, New South Wales. She copes with intense grief, anxiety, and a feeling of "floating" above her own life by distancing herself from reality. She has a rich interior world, often experiencing conversations with the ocean and the photographs she takes, though she struggles to process the trauma of losing her father at a young age. She acts as if everything is fine, camouflaging her social discomfort by mirroring her peers.

Jasper is a new kid at school who rides a motorcycle and has longish hair that covers his eyes. He walks with a limp caused by a severe car accident when he was eleven. He remains unfazed by the school's social hierarchy and quickly bonds with Biz over a shared sense of being outsiders, a love for poetry, and quiet moments by the ocean.

Sylvia is an energetic, humorous woman in her eighties taking a community photography class. She has a large extended family but lives alone following the death of her beloved husband. She welcomes Biz into her home, shares her darkroom, and serves as a surrogate grandmother who validates Biz's complex emotions without judgment.

Stephen is Biz's father, who died under tragic circumstances when she was seven years old. In life, he was a surfer with a sensitive disposition who struggled with the responsibilities of adulthood and parenthood, constantly changing jobs. In the present, he appears to Biz as a ghost, acting as a comforting presence who shields her from immediate anxieties.

Grace is Biz's oldest friend, sharing her taste in literature, music, and art. She explores her sexuality and manages the complicated, often toxic social dynamics of their high school peer group. Her sudden, passionate kiss with Biz sparks confusion for both girls, ultimately straining their bond as Grace leans into a new relationship.

Biz's mother works as a dental assistant and cares for her three children in Wollongong. She wants Biz to be happy and urges her to move forward from her father's death, often struggling to understand her daughter's profound emotional detachment. She proactively arranges professional help when Biz begins skipping school.

Bridgit is a clinical psychologist hired by Biz's mother to help the teenager process her intense grief and periods of dissociation. She focuses on teaching Biz how to manage panic attacks and suggests practical steps, like enrolling in a community class, to reconnect with the world.

Tim is a classmate of Biz and Grace who embodies the harmful behavior of their peer group. After forcing himself on Biz at a party, he invents a false story about their encounter, which leads to Biz being ostracized by her former friends.

Biz's younger stepsiblings are the product of a relationship their mother had after Stephen Grey's death. They are energetic fixtures in the household whom Biz observes with curiosity and affection.

Suryan is a student at Biz's high school who becomes romantically involved with Grace. His relationship with Grace accelerates the growing distance between her and Biz.