Richie, Potsie, and Ralph go on a trip to Chicago with the school choir. Not wanting to stay in their hotel room all night, they decide to sneak out and see a show.
Fonzie asks Richie to watch after his girl, Denise, while he's out of town at a demolition derby. Denise, upon hearing what Fonzie's asked Richie to do, decides to test Richie's trustworthiness. Richie succumbs to temptation and makes out with Denise at Inspiriation Point, but he later finds out that she has mononucleosis.
Richie is forced into being a disc jockey at a local radio station when one there suddenly quits. His boss informs him that he has the potential to become the next Wolfman Jack, and Richie begins to develop an inflated ego and neglect his friends.
To hide from overzealous fans, a popular rock group (one of the members was Richie's childhood friend) is staying at the Cunningham house, but Richie can't tell anyone that they're there. This poses a problem for Richie because nobody believes he actually knows them.
Howard secures a gig for Richie, Potsie, Ralph, and Bag to play at the Leopard Lodge dance. Fonzie is able to get the guys tuxedos, but, in return, he joins them as a member of the band. When Fonzie plays a loud bongo solo during a slow dance, Richie is chosen to give him the news that he's out of the band.
Looking for work, Richie, Potsie, and Ralph agree to fix the fence of an attractive divorcee. When the woman leaves for awhile, Potsie and Ralph decide to take off, as well, leaving Richie to finish the job by himself.
Facing a deadline for the school paper, Richie tries to get a photo of Clarabell the clown, from The Howdy Doody Show, without makeup. To get on the set, Richie plans to get Ralph to enter a Howdy Doody look-alike contest the show is conducting.
Richie, Postie, and Ralph are forced to go cruising for girls in Howard's DeSoto after Marion dents Richie's car at the supermarket. They find three girls but, later, find their boyfriends who are members of a gang called the Dragons.
Richie goes against Howard and, to get a girl, campaigns for Adlai Stevenson in the 1956 Presidential race.
An ill Richie is home alone after the rest of the family go to see Cinerama. When he goes to see what is causing noises downstairs, he finds a burglar.
Fonzie announces that he's getting married and brings his bride-to-be to the Cunningham house for dinner. There, Howard recognizes her as stripper he saw at a hardware convention in Chicago.
Richie and Potsie plan to host a poker night at the Cunningham house as Howard and Marion will be out of town. However, their plans change when three young women stop by after their car breaks down, and Potsie invites them to stay the night.
Howard wants Christmas Eve to only include the family, but Richie discovers that Fonzie will be all alone.
Richie, Potsie, and Ralph need new uniforms for their baseball team and want to get a big celebrity to play the title role in their upcomming fundraiser production of Hamlet. When they can't get a big name to play the part, Fonzie agrees to do it.
As a game-show contestant, Richie wins $3200 before time runs out for that week's show. After the show, he is given an envelope by the show's host that contains the answer to the $5000 question.
Spike, Fonzie's little cousin, takes Joanie out on her first date. Richie and his date act as Joanie and Spike's chaperones and discover them missing at the movie theater.
Richie wins a date with a movie star, Cindy Shea, to a school dance, and Gloria breaks up with him because of circumstances surrounding it. Cindy, however, will only be able to meet up with Richie after the dance has started.
After experiencing a few strange happenings, Richie begins to buy into the legend that the place where their Halloween party is to be held, the old Simpson house, is haunted.
Richie is named R.O.T.C. squad leader but has trouble controlling his squad. After several warnings to obey his commands, he puts them all on report.
Richie reads a book about abnormal psychology and begins to think that there's something wrong with him.
Richie's old girlfriend comes back to Milwaukee and wants to go steady with him.
Richie buys a car from Fonzie and finds out that it is stolen.
Richie feels that he doesn't have enough privacy, so he decides to move in with Chuck. He quickly discovers, though, that bachelor life isn't quite what he expected it to be.
