Grim's refusal to help Mandy win a martial arts tournament leads her to a curio shop, where the shopkeeper gives her the chicken ball that makes her the best fighter on Earth.
When Billy's mother realizes that Mandy has become an eternal houseguest, Mandy returns home. But her parents can't deal with her and they hire a nanny.
In order to become cool, Billy and Irwin Присоединиться a football team, so they won't get bullied anymore. Meanwhile, Mandy took over Mindy's position as the new cheerleader captain.
