Bobby gets caught up in Arlen High School's quest to get No Doubt to play their prom.
Through a series of mishaps, Bobby is mistaken for a freshman at Arlen High School. He delights in the joys of high school, such as better cafeteria food and bragging rights at the middle school. When he joins in the school's competition to get the band No Doubt to play their prom, Bobby's popularity soars. His popularity with Connie, however, plummets.
Bobby's so caught up in his web of deception - he told some seniors that he has a bad kidney, earning him the nickname Kidney Boy - that he forgets to buy tickets to the middle school prom. Connie is so mad she's agrees to go with Joseph, but not before Bobby has the high schoolers convinced that she has a hamster-like tail. When Bobby defends Connie and Joseph from a barrage of water balloons thrown by upper-classmen, he reveals his true identity. However, No Doubt is so sympathetic to Kidney Boy's "condition" that the high school bullies need him to show up to prom in order to get No Doubt to play.