An alien, Mork from Ork, comes to earth looking for someone average, or humdrum, to study and picks Richie.

With Richie in a dating slump, Fonzie sets Richie and himself up on a double date with two of his girls, Laverne and Shirley.

After being embarrassed at Arnold's by a couple of hoods, Richie wants to take a jujitsu class to learn how to defend and stand up for himself.

Marion, tired of the monotony of everyday house chores, decides to enter a televised dance contest. When Howard won't participate with her, she secretly enlists the help of Fonzie. Arnold unwittingly tells Howard that Marion has been at Arnold's early in the morning with another man, and Howard becomes suspicious.

Joanie enlists Fonzie to be her partner for a marathon dance at Arnold's. She desperately wants to outlast cheerleading captain Jill Higgins who had cut Joanie from the squad earlier. Prior to the dance, however, Fonzie's motorcycle breaks down, and he is forced to push it for 12 miles.

To allow Richie to have a night alone with his girl, Fonzie allows him to use his apartment and claim it as his own. Fonzie needs some rest, so he sleeps in Richie's bed without Howard, Marion, and Joanie knowing.

Thinking her life is dull and that she's always treated like a little kid, Joanie wants to join the Red Devils' gang.

Fonzie finds his his bike in pieces, and the search is on to find out who did it.

Needing to make a good impression for a prospective business deal, Howard asks Richie to take the ""Prince of Porcelain's"" daughter out on a date. Richie, however, already has big plans and asks Potsie to take his place and pretend to be him.

Joanie develops a crush on Potsie after he sings to her at Arnold's.

Lori Beth reports that Richie isn't moving after they crash his new motorcycle.

With nothing to do for the Easter holiday, Richie, Potsie, and Ralph decide to rent a cabin at Lake Whitefish. They pretend to be adult businessmen in order to secure the cabin and get girls.

After having been in several fights recently, on the advice of the Cunninghams, Fonzie agrees to see a psychologist.

Potsie saves Fonzie from a fire at the garage. Out of gratitude, Fonzie grants Potsie any one favor, and Potsie wants to pal around with the Fonz.

Richie makes a lucky shot to win a basketball game and suddenly becomes a big hero.

Facing a dating slump, Fonzie suggests that Richie go to the library to meet girls. Richie meets Lori Beth Allen at the library who invites him to her dorm room.

Worried that he's losing his cool, Fonzie attempts to jump 14 garbage cans on his motorcycle. The stunt will be televised on You Wanted to See It.

Fonzie crashes after a successful attempt to jump 14 garbage cans on his motorcycle and faces surgery to remove torn cartilage in his knee.

Kirk, the new acting sheriff, tries to exert his power by forcing Fonzie to leave town.

With Howard's hardware store about to face new competition, the Cunninghams decide they need to rent the room above their garage to generate extra income. Howard is shocked when Richie rents it to Fonzie.

Because the high school was vandalized, Officer Kirk imposes a curfew. Richie suggests that they demonstrate against the curfew, get arrested, and fight it in the courts. While Richie, Potsie, and Ralph are in the restroom at Arnold's discussing their plans, the lights go out, and they discover they are locked inside after Arnold closes up for the night.

Fonzie provides a drummer, who is black, to play with the band at Richie's party.

Arnold asks Fonzie to be the best man at his wedding, but Fonzie is resistant to the idea because of the "Fonzarelli curse." Arnold's fiance calls the wedding off when she thinks she'd be holding back Arnold's career.

Fonzie's adoption request is reconsidered after a stern talk by Howard to the adoptions administrator. Meanwhile, Joanie and Chachi continue to prepare for their wedding.

Fonzie poses as a police officer in order to stop a rumble between two rival gangs.