Howard wants to buy a bomb shelter to protect his family. Problems quickly arise when several of Richie's friends ask if they can use it.

Richie gets on the good side of a local gang, the Dukes, when he protects the leader's sister from being picked on. However, things change when the Dukes steal Potsie's bike, and Richie tries to get it back.

Howard's old army buddy, a black man, asks Howard to be the best man at his wedding. Howard and Marion consider holding the wedding at their home when the man can't find anyone else willing to do it.

Richie meets a beatnik named Diedre at the movies and gets caught up in her type of lifestyle.

Cindy, a new girl in school, asks Richie to tutor her. Richie is interested in more than just studying and makes several attempts to win her over.

Richie is put in an awkward situation when he is set up with a girl much taller than he is. Meanwhile, Howard is frustrated by Marion's ineptness at playing bridge.

To make some money, Richie, Potsie, Ralph, and Bag form a band. They secure a gig, but Richie and Potsie lose the money (including that of Ralph and Bag) playing poker.

Richie and his girlfriend, Arlene, break up after two weeks of dating. Neither of them have dates for the prom, so they end up going together as friends.

Richie and Potsie obtain fake identification cards in order to attend a burlesque show where Ralph says Bubbles McCall takes it all off.

After taking a look at a B+ Potsie got on an exam, Fonzie decides to drop back into school. He asks Richie to do his homework and cheat for him.

Richie and Potsie, in their never-ending effort to get girls, decide that they want to join a gang called the Demons. However, in order to be accepted, they have to perform several dares.

Richie buys tickets to a rock and roll show from Fonzie but has to work at the hardware store when Howard needs to have his tonsils removed. Because he'll be working until 9:00 PM, he won't be able to go to the show, so he asks Fonzie for a refund. Later, Howard tells Richie that he can close the store at 5:00 PM leaving him free to go to the show. He, now, has to ask Fonzie for the tickets back.

With Potsie's parents out of town for the weekend, he's staying with the Cunningham's, much to Howard's displeasure. The first night he's there, the boys learn that a classmate challenged Fonzie to a drag race in Ralph's newly suped car. When Howard discovers what the boys are up to, he goes down to where the race is taking place, and is soon picked up with the kids by the cops.

When Potsie is invited to his cousin who just came home from his service in the Marine's bachelor party, he invites Richie to go with him. While there, the boys get into trouble after participating in several drinking games.

Richie and Potsie talk Mr. C into letting them buy a car so Richie won't always have to borrow the family car. However, with the amount of money that the boys have pooled together, they can only afford a lemon.

Potsie sets Richie up with a girl known to have a reputation. Richie doesn't get far with her but leads Fonzie and others to believe he did.