A nostalgic comedy set in 1950s Milwaukee centered on the squeaky-clean Cunningham family and their relationship with Fonzie, a motorcycle-riding Casanova who became a pop-culture phenomenon during the show's heyday in the 1970s.
Joanie daydreams about the gang singing romantic Valentine's Day songs.
Wanting to be treated more like an adult, Chachi sells his soul to the devil. In order to get him out of it, Fonzie has to go 24 hours without receiving a kiss from a girl.
After hearing from a former employee about the wonders of television advertising, Howard thinks it will help his hardware store. He hires someone to handle the advertisement who guarantees a 40 percent increase in business in exchange for complete control of the project.
With the recent death of a fellow Leopard Lodge member, Howard fears that he may be ousted as Grand Poohbah for not attracting any new members other than Potsie during his five-year reign. He gets Fonzie, Chachi, and Roger to join as pledges, and they have to follow the orders of Potsie during their initiation.
Upset that the rest of the family is watching a football game instead of helping her prepare the Thanksgiving dinner, Marion reminds them of the meaning of the holiday with the story of the first Thanksgiving.
Fonzie's dog, Spunky, appears depressed and distant. After a visit to the veterinarian, it is determined that Spunky's problem is mental.
Lori Beth reports that Richie isn't moving after they crash his new motorcycle.
Thinking her life is dull and that she's always treated like a little kid, Joanie wants to join the Red Devils' gang.
The guys discover that Fonzie has been going to night school so that he can graduate with them. Marion gave them this information, and she becomes worried that Fonzie will be angry with her for telling.
Fonzie has to have his tonsils removed and will miss a big Halloween party.
Al tells Chachi about his dull, mundane life, so Chachi suggests that he ask his mother out. He shows up at Arnold's the next night disheveled and tells Chachi that his mother is already seeing someone. Chachi is shocked and vows to get to the bottom of it.
To get some publicity, Al tries to have someone break a world record at Arnold's. Meanwhile, Fonzie's cousin, Angie, is in town for a visit and proves to be extremely clumsy.
Chachi struggles with an essay on the causes, hardships, and influences of immigration until Fonzie tells him several stories in a series of musical vignettes.
Richie goes to a Leopard Lodge convention with Howard in Chicago despite wanting to go to a Bears game with Potsie and Ralph.
Fonzie comes to think that he is allergic to girls.
After getting a "D" on a paper for his investigative reporting class, Richie decides to do a story about the corrupt sanitation department that is forcing Howard to pay a weekly surcharge.
Richie, Potsie, and Ralph get an apartment of their own.
Richie and Lori Beth have a fight and break up before going on a weekend trip where the band is backing up Leather and the Suedes. Meanwhile, Howard and Marion argue about women's rights.
Richie makes up a story to tell Lori Beth when he's actually escorting a baton twirler to the fraternity dance.
Potsie secures an audition as a singer for a local club. The potential success goes to his head, and he treats those around him as inferiors.
Joanie brings home one of her students in an attempt to help her with her drug problem. The student promises Joanie that she'll make changes in her life, but she immediately takes several pills after everyone has gone to bed.
Ralph is caught with the girl of the football team's star fullback, Rebel E. Lee. Instead of a fight, Fonzie arranges a boxing match between Rebel and Ralph to settle their dispute.
Fonzie receives a Christmas gift from his father but is reluctant about accepting and opening it. Meanwhile, Richie and Lori Beth argue about what they've spent on each other's gifts, and Joanie is upset at Howard for getting an artificial tree.
After one date with Jennifer Jerome, Potsie wants to ask her to marry him. Howard suggests that they get pinned instead, but, after asking her, Potsie suddenly backs out.
After passing make-up health exams and getting permission for Fonzie to participate, the guys arrange for aspects of the graduation ceremony to be sped up in order to accomodate the inclusion of Fonzie's speech.