Bianca is enjoying her senior year of high school with two close friends Jess (Skyler Samuels) and Casey (Bianca A. Santos)– who are significantly more popular than she is. She is also the neighbor and former friend of Wesley (Robbie Amell), a star on the school’s football team. She has a crush on guitar-playing Toby (Nick Eversman), and reluctantly attends a party hosted by mean-girl Madison (Bella Thorne), hoping to talk to him. The party turns out to be a disaster for her, as it’s there that Wes unthinkingly reveals to her that she is the “DUFF” of her friend group, the “Designated Ugly Fat Friend.” The DUFF need not actually be ugly or fat, he explains, it’s just the person in a social group who is less popular and more accessible than the others in the group. People exploit the DUFF to get to the popular people.