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.

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.

Joanie daydreams about the gang singing romantic Valentine's Day songs.

Chachi is hesitant about asking girls out for fear that he will be rejected. Fonzie tells Chachi that girls will ask him out because he has the Fonzarelli power.

After having to borrow money from Marion and being hassled by Fonzie about being a bum, Chachi takes a job as a dance instructor. Meanwhile, Howard takes away Potsie's salary after he sells power drills for $13.05 less than cost.

After his single makes it onto the record charts, Chachi is invited to go on tour with the Beach Boys as one of their opening acts. However, he quits the tour after learning he has diabetes.

After being nothing more than a coatrack for Fonzie's scarf during a rumble, Chachi enters the city boxing championship tournament to earn his respect. Fonzie is elated when Chachi wins his first fight.

Fonzie is given the job as teacher of auto mechanics at Jefferson High School. He gets frustrated when his students don't pick everything up as quickly as he did when he was a kid.

Chachi tells Fonzie that his motorcycle has seen better days, but Fonzie refuses to junk it. He finally decides to get a new bike after crashing his old one but has to save his money a little longer. Joanie suggests to Chachi that they all pool their money with Fonzie's to surprise him with a new bike for his birthday. Meanwhile, Arnold's has a new cook, but Fonzie's sixth sense tells him that something isn't right about him.

After a day of everyone asking favors of him, Fonzie has a nightmare about a mad scientist draining his cool.

Fonzie is rejected several times by a new teacher at Jefferson High. After he kisses her in a final attempt to win her over, she screams and runs out of the house. Roger talks to her and finds out that she is a nun.

Al is chosen to head the Leopard Lodge's annual Poobah Doo Dah when he says he can get his distant cousin, Frankie Avalon, to perform. However, as Al is auditioning other acts to round out the show, Avalon calls to say he can't make it.

Initially furious that the music teacher, Cynthia Brannigan, hires the Boston Conservatory Orchestra for the annual Jefferson High concert, Fonzie changes his tune when he realizes that famous composer Tchaikovsky was very much like himself. Fonzie decides to get the entire Jefferson High gang to like classical music.

Roger's family sends his brother, Flip, to Milwaukee with the hope that Roger can straighten him out. Roger entrusts Flip to pick up Marion after he attends a Fats Domino concert, but he skips the concert to hang out with some hoodlums and leaves Marion to walk home in the cold.

Joanie and Chachi have the opportunity to appear on a television music show but learn that their format is folk. Meanwhile, Fonzie is upset that folk music seems to be replacing rock and roll.

A record producer hears a demonstration tape of Joanie and Chachi and is eager to sign them. However, Chachi has an argument with Mario, a member of the band, and says they're breaking up.

Fonzie babysits Heather when Ashley leaves for a tax seminar, but his attention is drawn away by a televised heavyweight title fight leaving Heather resentful toward him. Meanwhile, Joanie and Chachi return to Milwaukee after Joanie says she's sick.

Howard decides that it is necessary to build a second bathroom after he's forced to shave at the dining room table. To save money, he decides to allow Fonzie's students to build the room. Howard doesn't realize that the room will take all semester to complete, and this hurts his plan to make a killing in whisper-quiet toilets. He fires Fonzie and the students and says he'll finish the bathroom himself.

Howard is jealous and upset when Marion's high-school boyfriend, Frederick, comes to visit. He becomes enraged when Frederick takes Joanie out on a date.

Lori Beth receives a letter from Richie in which he proposes marriage. She has to go to Greenland for the wedding, but doesn't have the money to make the trip. Marion goes on a show called Dreams Can Come True in which three women tell their stories of tragedy. The winner has their dream come true, and Marion hopes she can win the money for Lori Beth.

After a day of fishing with Howard, Chachi gets to thinking about his future when he realizes that being a success in the music business is a long shot. He leaves the house determined not to come back until he finds a career that would be sufficient to support Joanie should they get married one day. He tries his luck at being a salesman.

Fonzie and Roger miss their flight to Minneapolis for a teacher's convention, so they agree to go with Potsie's uncle, Omar, who has a small plane he uses for crop dusting and spreading ashes. Omar jumps out when there is trouble with the engine leaving Fonzie and Roger by themselves with no parachutes.

Jenny dumps a nice guy to be with a former Olympic swimmer, but K. C. learns that the swimmer doesn't feel the same way about Jenny as she feels about him. Meanwhile, Fonzie wants to have a swimming pool put in the Cunninghams' backyard.

Fonzie finds a note he wrote as a child containing a list of things to accomplish in the next twenty years. On the list is one goal he hasn't yet accomplished: climb Suicide Hill on a motorcycle. The problem is that he's already tried it and failed.

The gang stages a rodeo in an attempt to raise money to pay off the note H. R. Buchanan holds on Marion's Uncle Ben's ranch.