Sixteen-year-old Vivian lives with her mother Lisa and attends Rockport High School. One day she joins her best friend Claudia at an exclusive class taught by Mr. Davies, where she notices that her classmate Seth “The Shrimp” has gotten taller and more attractive over the summer, and meets the new student, Lucy. Mr. Davies then begins a discussion of
The Great Gatsby, a novel about a mysterious millionaire. Lucy criticizes it as "another tale of a rich white guy expressing sorrow over not having the woman he wants." The star
jock Mitchell interrupts her opinion, defending the character of
Jay Gatsby. Later, Vivian sees Mitchell taking the soda Lucy was trying to buy, harassing her, and spitting in it. When Lucy reports him to Principal Shelly, she does not want to penalize Mitchell and tries to avoid getting involved. Through her newfound friendship with Lucy, Vivian begins to notice sexism throughout the school treated as casual. At home, Vivian goes through Lisa's stuff, finding her old feminist
zines which inspire her. The next day at school, the students receive a sexist and perverse list from the jocks, which calls out many of the girls, embarrassing them, but which the boys all find "hilarious"; Mitchell calls Lucy a foul word. Vivian becomes inspired by her feminist mother and starts "Moxie", a zine aimed at
calling out the unfair treatment of girls at the school, and empowering them to raise their concerns. Vivian keeps "Moxie" a secret to everyone except a few other girls who have been put down, like Lucy and Claudia. Seth learns that Vivian created "Moxie" and, understanding the feminist cause, is proud of her, so Vivian and Seth begin a relationship. Claudia, however, is less proud, and is unsure about the idea of the zine. The girls champion Kiera, captain of the school's state champion soccer team and one of them, to win an athletic scholarship, but Mitchell, quarterback of the losing football team, receives it instead. Vivian walks home feeling depressed, drinking the bottle of champagne meant for Kiera's win along the way. She comes home to find Lisa with her boyfriend John and is annoyed that her mother kept the relationship a secret from her. Vivian then throws up. Later, the "Moxie" girls respond to Mitchell winning the award by putting crude stickers all over the school. Principal Shelly, who was called out by "Moxie" for not supporting the girls, attempts to shut down the group. Claudia, who joins the group, takes the fall for the stickers, but confronts Vivian for not coming forward about starting "Moxie". Vivian starts to go through a rough patch with Seth. She then faces challenges with Lisa when Seth comes over for dinner with her mom's new boyfriend John and creates a scene. When confronted, she confesses that she started Moxie and expresses her grief over her late father. Vivian finds a note from an anonymous girl who says she was raped the previous year. Vivian gets "Moxie" supporters to stage a
walkout in support of the girl. The majority of students participate, and Vivian reveals to the rest of the school that she started "Moxie". Head cheerleader Emma comes forward as the rape survivor, stating that her ex-boyfriend—Mitchell—was her rapist. It happened the previous year after prom when they were dating. When she was called the "Most Bangable", it left her mortified. All the students are horrified and lend their support. Principal Shelly overhears and plans to punish Mitchell at last for the rape and his sexist behavior. Vivian reconciles with her mom, Claudia, and Seth, and "Moxie" gains more followers. Lisa expresses pride in her daughter and the girls throw a party in celebration of "Moxie". ==Cast==