Debbie is a 14-year-old girl living in the midwestern town of Seldem. She feels tired of her predictable life and desperately wants something interesting to happen to her. She spends her summer days listening to the radio with friends in a parked truck, experimenting with new fashion trends like bell-bottom jeans, and quietly observing the people around her. She occasionally sifts through her mother's old yearbooks to understand what young womanhood looks like.

Hector is a 14-year-old boy who often feels awkward and plain compared to his self-assured older sister. An unexpected trip to a community college coffeehouse awakens his interest in music and playing the guitar. He signs up for lessons at a local church, hoping to express the complex emotions he struggles to articulate. He frequently questions his appearance and worries about how he measures up to other boys in his class.

Lenny is a 14-year-old boy with a highly mechanical mind. He often spends his time alone or sitting in his father's parked truck in the driveway. He enjoys reading encyclopedias, fixing bicycles, and emulating his dad's habits, such as chewing tobacco. He offers a steady, pragmatic presence in his social circle while privately harboring a deep curiosity about how the universe functions.

Patty is Debbie's closest confidante and an active member of their neighborhood friend group. She frequently stays up late engaging in deep conversations about serendipity, soulmates, and the universe. She shares Debbie's desire to experiment with new styles, occasionally hiding in bushes to change into trendier clothes without their mothers finding out.

Phil lives on the same block as Debbie, Hector, and Lenny. He is a supportive, steady presence in the group who enjoys playing basketball. He acts as a reliable sounding board for his friends' anxieties, easily absorbing their confessions without casting judgment.

Rowanne is Hector's 17-year-old sister. She carries an aura of confidence that her brother admires and often seeks to emulate. Rather than dismissing her younger sibling, she actively includes him in her life, offering him rides to events and patiently listening to his adolescent troubles.

Mrs. Bruning, also called Grosi by her family, is an elderly woman living alone in Seldem. She manages arthritis and diabetes, requiring assistance with weekend chores like cleaning gutters and organizing papers. She enjoys sharing stories about German language and culture with her visitors.

Peter is Mrs. Bruning's grandson, visiting Seldem from California for a few days. He is an empathetic boy who enjoys discussing literature, travel, and philosophy. His arrival interrupts the neighborhood's static summer routine and offers Debbie a fresh perspective on life outside her small town.

Dan is the school's popular, athletic football star. He signs up for summer guitar lessons at the local church basement. His natural confidence and conventional attractiveness tend to make the other boys feel insecure, while easily drawing the attention of his female classmates.

Meadow is a girl in the summer guitar class with a careless braid of chestnut hair and a quick smile. She is friendly and chatty, quickly catching the attention of multiple boys in the class. She spends time going to the local Tastee-Freez and summer fairs.

Helen is Debbie and Chrisanne's mother. She maintains a consistent, safe presence in her daughters' home life while occasionally clashing with Debbie over modern 1970s fashion trends. She keeps boxes of scrapbooks, yearbooks, and photographs from her own youth in the spare bedroom.

Chrisanne is Debbie's older sister. She has a collection of magazines and cosmetics that fascinate her younger sibling. She spends her summer days sunbathing in the yard with her friends.

Leon is Lenny's father. He works on physical projects around the house, from moving old washing machines out of the cellar to roasting a pig for the neighborhood block party. He allows his son and his friends to hang out in his parked truck.

Russell is an awkward but congenial teenager taking guitar lessons. He accidentally discovers a lost necklace with Debbie's name engraved on it while walking through the neighborhood, carrying it in his pocket until it falls out again.

Pastor Don runs the local guitar class for a mix of older adults and teenagers. While he is not a professional-level musician, he plays enthusiastically enough to encourage his students to start singing along.