It focuses on Fonzie winning a fight (or, as they call it, a "hollitacker"), with an alien known as Mork from Ork. Mork decides that someone who can win against him cannot live on Earth, so he "neutralizes" him by turning him into a girl.
Fonzie doesn't want to admit to anyone but the Cunninghams and Chachi that she's Fonzie, so she goes by Francine, or "Francie" and claims to be Fonzie's cousin from Chicago (and that Fonzie is in Chicago). She also has to deal with the things that come with being a girl, like being flirted with by guys and having breasts.
Unfortunately, there's a bit of sexist stereotyping in this fanfiction, with Mork thinking that turning Fonzie into a girl will make him incompetent and believing that she now "belongs" to Richie. There's also several characters who think that women can't be mechanics or that they have to be "ladylike".
Happy Daze contains examples of
- Alien Episode: Downplayed. The alien is a major plot point but doesn't take up most of the fanfic.
- Aliens Speaking English: Mork mainly speaks English, with a few nonsense words thrown in.
- Alliterative Name: Potsie's real name is Warren Weber and Fonzie's alias is Francine Fonzarelli. There's also a Paula Petrolunga mentioned.
- Catch Phrase: Fonzie still says "Ay!".
- Fantastic Racism: Mork seems to view humans as "inferior".
- First Law of Gender-Bending: Fonzie stays as Francie.
- Gadgeteer Genius: Fonzie is very good with technology.
- Gagging on Your Words: Fonzie has trouble saying, "You win".
- Gender Bender: The main plot revolves around Fonzie becoming a woman.
- Human Aliens: Mork looks like a human.
- In-Series Nickname: Arthur Fonzarelli gets called "Fonzie" or "The Fonz". As Francine Fonzarelli, she gets called "Francie". Richard Cunningham also gets called "Richie" or "Rich", Joanie gets called "Shortcake", and Bill Wallenska gets called "The Wall".
- Known Only by Their Nickname: Fonzie. Also Potsie.Francie: "You're the only one who calls me Arthur, even Father Delvicchio calls me Fonzie."
- Last-Name Basis: Fonzie (including as Francie) calls Richie "Cunningham".
- Limited Wardrobe: Fonzie is described as being "dressed, as always, in jeans, a white T-shirt, and his precious leather jacket".
- Mating Dance: When Richie and Francie dance, it makes them feel "tingly" and they find it sensual.
- Mr. Fixit: Fonzie is good at fixing cars and bikes just like in the series.
- OOC Is Serious Business: When Fonzie turns female, she starts neglecting her hair, which Mrs C thinks must mean that Fonzie is sick to do that.
- Soup Is Medicine: Marion serves Fonzie chicken soup, because she believes he has a cold.
- Spell My Name with an "S": Marion is referred to as "Marian", Potsie as "Potzie" and Ralph Malph as Ralph "Malf".
- Spell My Name with a "The": Fonzie calls himself "The Fonz".
- Teleportation: Mork teleports across a room around the beginning.
- Third Law of Gender Bending: Downplayed. Even though Francie doesn't have to wear dresses, heels or skirts and she can still be a mechanic, Marion does say that she needs to wear "feminine" tops and pants, make-up and jewelry.
- Wrench Wench: "Francie" is still a mechanic and is met with prejudice.