Andy French (a part-time water bed salesman with dreams of being a cartoonist living with his drinking buddy, Jim, and a hippie girl named Posey) is forced to take in his geeky genius brother, Kevin, after Andy's parents announce that they're moving to Wyoming and not taking any children with them.
Kevin faces a moral dilemma when two bullies (Griffo and C-Dog) get blamed for burning down the Mission Hill market, which was an accident Kevin caused after trying to hide a pornographic magazine after one of the bullies catches him masturbating to it. Meanwhile, Jim returns from Japan wearing Day-Glo short-shorts which becomes popular with everyone,except Andy.
George Bang's sister, Tina, comes to town for a science fiction convention and causes a rift between Andy and Kevin as they both vie for her affection. Meanwhile, Gus gets a knife stuck in his head, and vexes Wally by not going to the hospital to get it removed.
Kevin, George, and Toby attempt to crack the "code" of the SAT in order to get perfect scores. Meanwhile, Posey's massage parlor business venture attracts men who think the massages lead to sex.
After having his work rejected, Andy decides to abandon his dreams as a cartoonist and become Ron's assistant at the water bed store, which changes Andy's personality for the worse.
Part one of two. Andy finds himself unemployed when his boss, Ron, gets arrested for tax evasion and the water bed store is seized by the government. When Andy can't hold down a job, Kevin goes to Ron to sign a form that activates Andy's unemployment payment--and becomes the owner of Ron's sports car.
Conclusion. Andy discovers that Jim has a successful career at an advertising agency, and decides to quit being a slacker and get a job as an ad agency artist.
When Andy attends Kevin's parent-teacher conference in lieu of their mother and father, he joins the PTA in order to impress Kevin's attractive English teacher. Meanwhile, Kevin becomes obsessed with an online role playing game.
Kevin finds a collection of old videos chronicling the time that MTV's The Real World filmed a season in Mission Hill--and how Andy became part of the cast after one of the house mates got hit by a bus.
Kevin asks out Eunice Eulmeyer, the weirdest girl at his school, in the hopes that her famous scientist father will write him a letter of recommendation for college. Meanwhile, Andy, Jim, and Posey are denied admission to a new nightclub, prompting them to create their own nightclub.
Andy is asked to the Grammys by actress Becca Michelle Butterfield; Posey meditates in an attempt to find nirvana; and Kevin gets involved in a protest when news of an international crisis hits.
When Kevin becomes depressed that no one in the city cares about his birthday, Andy attempts to cheer him up by throwing him a party. Meanwhile, Natalie raids an animal testing lab and brings home a snake as a pet.
Kevin becomes fascinated with classic films after watching "Midnight Cowboy" (under the assumption that it was a porno because of its "X" rating)--and uncovers an unseen B-movie Wally directed in the 1950s.