From now on, the only boys Penny Lane Bloom wants to be romantically involved with are John, Paul, George, and Ringo. After all, the Beatles are just about the only guys who haven't broken her heart. After her dream guy turns out to be a nightmare, Penny makes a decision to give up dating for the rest of her high school years. She's sick of boys lying and cheating. But most importantly, she hates it that so many girls, like her old best friend Diane, give up their identities, interests, and friends after they "fall in love".
When Diane is dumped by the same guy that she dumped all her friends for, Penny welcomes her into the newly-founded Lonely Hearts Club.
The rules of the club are simple: absolutely no dating allowed. Members are also required to attend all couple events (like homecoming and prom) as a group, have club meetings every Saturday night, and always be supportive of their friends—including unfortunate hair, wardrobe, and music choices.
Penny's personal decision quickly takes McKinley High School by storm. What happens when one girl takes the focus of nearly the entire female population of her school off of dating, and redirects it on friendship? Can Penny handle being a local non-dating legend…especially when there's one boy she might be falling for?