An unpopular, hyperactive teenage boy named Fred Figglehorn who wears childish dungaree and striped t-shirts as though he's five and believes he's cool and a good singer (he's not) has an infatuation with a girl named Judy, but is devastated to see her performing a romantic duet with his rival Kevin during music class one day. Because of this, Fred aspires to one day sing a song with Judy. However, after an attempt to dig his way to her house in order to avoid obstacles such as Kevin's harassment, he discovers that she has moved. So, Fred embarks on a journey to find Judy's new house and sing with her there.
During the quest, Fred encounters different characters, including an anthropomorphic deer, a bedraggled, matured childhood friend who had gotten lost in the forest years earlier (known as Little Evan Weiss), a neighborhood girl named Bertha, and a boy with a personality opposite his own named Derf. However, after arriving at Judy's home, Fred discovers that she is hosting a party that he was never invited to. Fred is bullied by her guests for his poor social status at school and eccentric personality. Kevin then shoves a pizza onto Fred's shirt, causing him to vomit on Judy's party dress. Miserable, Fred leaves the house and is infuriated to find that Kevin has posted a video of him vomiting on Judy online, so he decides to throw a party of his own and not invite anybody to get revenge for excluding him from Judy's party. In order to deceive others into believing that he has held a spectacular house party, Fred invites Bertha to his house where they costume mannequins in different outfits and clown around, and after Fred has altered the video the two recorded of the fake party he posts it on the internet, where his peers watch it and are misled into believing that Fred and Bertha actually held an extraordinary party. Soon, Judy visits Fred's house and asks if the two may sing together, and Fred accepts the request.