Del is a 17-year-old high school junior who harbors a long-standing crush on his classmate, Kiera Westing. When he inadvertently signs up for an eight-week Purity Pledge program at church, he decides to stay in the group to get closer to her. He receives conflicting messages about masculinity and sex from his father, his best friend Qwan, his school's sex education class, and the church's abstinence program. He spends his time trying to present himself as the perfect match for Kiera while secretly funneling sex education answers to his church peers.

Kiera is a devout high school student who recently broke up with her long-term boyfriend, Colossus. She takes her religious convictions seriously and joins the Purity Pledge to make a commitment to abstinence. She is protective of the younger girls in the pledge class and is highly skeptical of Del's intentions due to his social reputation. She uses her natural leadership skills to guide the pledge activities and strictly maintains boundaries when Del tries to push their friendship into a romance.

Cressie is Del's older sister who is currently in her first year of college. She runs a growing YouTube channel called FemFam, where she discusses sociology, women's rights, and the double standards young women face. She returns home to work on a sociology project, focusing her interviews on the disparate treatment of teen mothers and fathers in their hometown.

Pastor Newsome is the strict leader of the church and the overseer of the Purity Pledge class. He enforces absolute obedience from his congregation and frequently uses public shaming to maintain control. He strongly opposes the high school's sex education curriculum, believing it corrupts the youth, and he actively questions Del about the school's teachings.

Jameer is an honor roll student, Kiera's next-door neighbor, and a participant in the Purity Pledge class. He lives with extremely strict, conservative parents who monitor his internet access, remove his bedroom door, and mandate his participation in church activities. He leverages his friendship with Kiera to persuade Del to answer his health questions using information from the school's sex education class.

Qwan is Del's best friend who actively pursues girls and avoids emotional attachments. He frequently gives Del advice on how to aggressively pursue Kiera and pressures him to prioritize sexual conquests, reflecting the typical masculine expectations of their peer group. He pays close attention to school gossip and spends considerable time texting Angie Bell.

Mister Jay, known as MJ to his students, is Del's favorite teacher. He instructs both English and the school's newly updated Healthy Living curriculum. He provides factual, straightforward answers about sexual health and contraception, establishing himself as a trusted adult figure. He openly shares respectful stories about his wife, offering his male students an alternative model of masculinity.

Sister Vanessa is the instructor for the Purity Pledge class at the church. She guides the teenagers through discussions and activities focused on remaining abstinent until marriage. She pairs the boys and girls for church activities to demonstrate respectful interactions and maintains a watchful eye over the youth group.

Mya is Del's shy coworker at the fast-food restaurant and a fellow member of the Purity Pledge group. As they work together in the drive-thru and cashier stations, she bonds with Del over their shared love of comic books and science fiction. She introduces Del to new graphic novels featuring strong Black female leads.

Shianne is a classmate of Del's and one of the nine girls who became pregnant the previous year. She and Del share a secret regarding a party from their freshman year. Outspoken and unafraid to challenge social norms, she hires Del as a tutor so she can manage her schoolwork while caring for her newborn baby.

Del's father is a supportive but traditional man who encourages his son to pursue romantic conquests. He views sexual activity as a rite of passage for the men in their family, a perspective that influences Del's internal conflict. He enforces household rules and monitors Del's employment status at the fast-food restaurant.

Del's mother is a caring parent who encourages her family's church attendance. She is proud of Del's apparent commitment to the Purity Pledge, unaware of his true motivations for joining. She maintains the family schedule and coordinates closely with her husband on disciplinary matters.

Colossus is Kiera's recent ex-boyfriend. He frequently interrupts Kiera's new activities in an attempt to win her back after being unfaithful. He is also the center of school gossip regarding his connection to Taylor Burkin, one of the school's pregnant students.

Angie is a student at Green Creek High School who faces intense social media harassment after rumors spread about her involvement with Colossus. She walks quickly through the hallways to avoid the derogatory comments from her peers and eventually develops a connection with Qwan.

Taylor is one of the high school girls who recently had a baby. She uses social media to publicly demand accountability from her child's father, pushing back against the double standards that shame teenage mothers. She agrees to be interviewed for Cressie's YouTube channel to share her story.

Jaylan is a famous YouTube personality who advocates for women's rights, sex education, and mental health. Her upcoming speaking engagement at the local university becomes a major focal point for Cressie and the Purity Pledgers.

Mason is a high school student who works for a landscaping company. He trims the shrubbery at Kiera's house and begins flirting with her, quickly becoming a source of intense jealousy for Del.

Tyrell is the manager at Monte FISHto's where Del and Mya work. He monitors Del's work ethic, enforces uniform rules, and manages the restaurant's shifting schedule.

Ramsey is an older friend of Jameer who drives him home. He provides transportation when Jameer needs to bypass his parents' strict curfews and social limitations.

Ralph is a member of the Purity Pledge class. He participates in the group's coordinated plans to help Del secure alone time with Kiera.

Bobby is a member of the Purity Pledge class. He assists his brother Ralph and the older teenagers in their various schemes during church events.