I Want My Beloved to Be Fashionable

So you've fallen in love with the shy girl with glasses, or the Lovable Nerd, or the frumpy Nice Guy. And they're the absolute apple of your eye, except... The Glasses Gotta Go. And maybe you can get them some nicer clothes; that Rummage Sale Reject outfit belongs in the trash. They'll look great with a little work, so it's perfectly OK for you to insist on The Makeover, right?

I Want My Beloved to Be Fashionable is where falling in love kicks off a burning desire to change the beloved (for the better, really!), usually by making them stand up straight and color-coordinate their wardrobe. It sometimes occurs as a result of Underdressed for the Occasion. Truth in Television.

Opposite of the Pygmalion Plot, where a burning desire to change someone results in falling in love. May still result in Pygmalion Snapback if the beloved likes being a frump.

Examples of I Want My Beloved to Be Fashionable include:

Anime and Manga

Boys Over Flowers: Rich jerk Tsukasa gets a crush on average girl Tsukushi and has her kidnapped for an impromptu makeover.
Butterflies, Flowers: Director Domoto harasses Office Lady Choko into dressing more genteelly.
Konoka in Mahou Sensei Negima sometimes likes to do this to Setsuna. Pretty much the girls's entire wardrobe was selected by Konoka (she normally just likes her school uniform).
In Ouran High School Host Club, Tamaki (and the twins) constantly attempt to get Haruhi into pretty dresses. This is a rather odd example, since Haruhi is hardly unnattractive... but hardly attractive in the manner of most girls.
Tomoyo insists on making outfits for her beloved Cardcaptor Sakura, although she restraints herself to only making "battle costumes" (teddy-bear-gifting notwithstanding).

Comic Books

In Ultimate Spider-Man, Harry comments that M.J. should stop wearing glasses because she looks "way hot without them". M.J. counters that she looks "way hot with them". The reader's probably going to side with M.J., particularly the way David Lafluente draws her.
One Elf Quest: New Blood story has Ahnshen, the weaver and tailor of the Sun Folk, wanting to give Moonshade a makeover. It's tied up with his idea that she should be a "gentle flower" rather than a "savage and frightening" huntress. Seeing her all dolled up is what convinces him he was wrong.

Film

In Patriot Games, Jack Ryan's wife insists that he get some fancy suits when they visit England.
In Irma La Douce, Irma, a prostitute, wants to make sure Jack Lemmon, her new mec (a French word which roughly translates as "pimp") wears the nicest clothes to show how much she loves him.
Inverted in Casino Royale: James Bond and Vesper Lynd are upgrading each other's wardrobes before their relationship has gone very fast past strictly professional.

Literature

Mary Crawford, a Romantic False Lead in Mansfield Park, falls in love with Edmund Bertram but refuses to marry him unless she can get him to choose a more lucrative profession than the clergy. She can't.
In Ovid's Metamorphoses, Apollo falls for the nymph Daphne, who spends all her time running around in the woods, sees her loose hair, and immediately thinks, "What if it were pinned up?"
Non-romantic example: In Jeeves and Wooster, Jeeves keeps Bertie's clothing within certain guidelines, sending back, giving away, or utterly destroying anything he doesn't like. Since Jeeves is Bertie's valet, this would seem natural, except that it's Serious Business and leads to high levels of dramatic tension (Played for Laughs) between the two. If Bertie insists on wearing something Jeeves disapprove of, the latter's reactions range from frigid and distant to utterly heartbroken.

Live-Action TV

The Korean Series Boys Before Flowers shows us Lonely Rich Kid Jun Pyo giving Ordinary High School Student Jan Di a complete wardrobe change for a weekend tropical trip.
The Reality TV series Extreme Makeover is completely made of this trope, as is How Do I Look. The series Ambush Makeover is more like "I want random strangers on the street to be fashionable".

Newspaper Comics

Therese does this to Anthony in For Better or For Worse.

Theatre

In the number "Take It Like a Man" of the musical version of Legally Blonde, Elle Woods takes Emmett Forrest to a department store for a makeover so that he can look professional for the upcoming court case.
Wicked: When Galinda and Elphaba decide they can stand each other's guts after all, Galinda's first order of business is to bust out into the song, "Popular," and completely change the way her green friend looks and acts. Granted, this is a friendship-oriented example, but the amount of Les Yay between the two might allow it to qualify.

Western Animation

Disney's Oliver and Company ends with the literal Rich Bitch poodle accidentally scaring off the Plucky Comic Relief/Chew Toy, who'd been hitting on her for the whole movie, with this trope.
In The Simpsons episode "Lisa's Date with Density," Lisa takes her crush Nelson Muntz shopping for spiffier clothing. "I feel like such a tool," he says, seeing himself in the mirror with a collared shirt and sweater vest.