Reluctant Fanservice Girl

Any more great ideas? Why don't you strip down and have a hundred people stare at you!?

—Sue Storm from Fantastic Four

If the writer or artist wants to include a ridiculously sexy female character who is always dressed in skimpy outfits, he may choose to give a reason for this character to dress and behave the way she does. Maybe she's The Vamp, and is using it as a means to get what she wants from men, or maybe she's the Innocent Fanservice Girl, who simply doesn't know- or doesn't care- about the effect she has on men.

Then, there's this girl. She would prefer to dress modestly, and really doesn't like being ogled by men, but, for some reason, the universe conspires to have her dress in skimpy outfits or end up naked. Her clothes may get ripped or stolen, she may be pressured into it by her friends, she may have to serve as a sexy distraction for the idiot guards, the villain may have kidnapped her and forced her to wear a metal bikini... any excuse will do, but whatever the reason, she will always be unhappy about it.

Often played for laughs as a form of Butt Monkey-ness, although serious variants are also possible. After all, much of the humour of the situation depends on whether you think women being unwillingly stripped down carries a host of Unfortunate Implications, or is as harmless as any other fictional kink. If the author wishes to make a point about gender issues, this kind of Fan Service will often be toned down or Deconstructed.

A frequent consequence of the Third Law of Gender Bending. This sort of thing may also happen to the Mr. Fanservice.

Examples of Reluctant Fanservice Girl include:

Anime and Manga

Ranma-chan often finds herself in this position in Ranma ½. Especially if Happosai is around.
Mikuru Asahina from The Melancholy of Haruhi Suzumiya. Haruhi is constantly trying to invoke tropes, and uses Mikuru for her appeal and tries to make her the Innocent Fanservice Girl, much to Mikuru's depair. While she eventually accepts her Meido outfit, she is still struggling to accept it when Haruhi tries to put more revealing outfits on her.
This is the entire concept of Maicchingu Machiko Sensei. The titular character continually finds herself naked due to the actions of her perverted students, the occassional non-human, or the nature of the universe itself.
A dozen examples could be found from Mahou Sensei Negima alone, Takane D. Goodman being the most notorious.
- Further information: Takane is in the habit of using magically-generated clothing instead of actual clothing, and so her outfits tend to vanish completely whenever she's defeated in battle... and she's not exactly the most powerful side-character.
- This is also known to happen to Asuna. Early incidents involved Negi's wind magic activating by accident, which blew off all Asuna's clothes without causing her any harm. This could be taken as Foreshadowing of her special abilities.
  - Negi's wind magic accidentally activating has done that to many girls, not just Asuna. The fact that his attempt to erase her memory also resulted in nothing more than clothing loss for Asuna, however, was foreshadowing of Asuna's magic cancel abilities. And recently, her magic canceling abilities became so strong that she kept her clothes on when Negi's infamous strip-sneeze came around.
Gray from Fairy Tail is a male example. His training to resist the cold left him with a habit of stripping down to his boxers without realising, and he's always embarrassed to find out he's half-naked.
- Another example from Fairy Tail is Lucy, whose clothing always manages to rip just enough to cover the naughty bits. She's understandably not very happy about it.
Mio Akiyama from K-On!. She's been forced into her share of costumes, not to mention tripping over a cord and landing in a panty-exposing position during the band's first performance in front of the whole school.
In Yaoi, the Uke sometimes take this role in relation to the Seme. And the audience.
Yuki from Fruits Basket, especially when he's forced to wear a beautiful girl's kimono for the school festival.
Yu-Gi-Oh!: In the virtual world mini-arc, Joey is forced to wear a the garb of a legendary warrior: a one-shouldered "barbarian" style garment cut very short. It's even skimpier than Mai' costume—although she's extremely comfortable in hers and Joey tries to avoid coming out in his.
In the Hentai Dragon Pink, Pink is constantly being humiliated in this way.
Infinite Stratos: Charlotte Dunois often mentions not minding nudity around Ichika, but would prefer that he ask first, yet still chides him for perversion.
Kallen from Code Geass has fallen into some precarious clothing and/or pose situations, to the point where part of the fanbase considers her nothing more than fanservice.
Ultimate Girls
The condition for Ringo's jumping power in Banana no Nana is that she has to wear a miniskirt that shows off her panties.
The Magical Girl outfit in Okusama wa Mahou Shoujo is designed for your standard, young girl. Ureshiko, at 26, has a fully adult body, and she's not quite comfortable when people point out how it looks on her.
Blue Rose in Tiger and Bunny is contractually obligated to go crime fighting in a Stripperiffic outfit despite how impractical and dangerous it is. Mainly because her sponsors market her largely on sex appeal.
Asuka Tenjouin from Yu-Gi-Oh! GX. Unlike Mai from the original series (who was a shameless Attention Whore) Asuka really doesn't like the fact that most boys at Duel Academy are drooling over her. This is emphasized in the manga version, where she practically had to be dragged to a beauty pageant to compete for a title she had been nominated for.

Comic Books

The entire point of Empowered.

Film

Leia in Return of the Jedi, seeing as she was forced to wear the infamous "titanium thong" (as Carrie Fisher called it) as Jabba's prisoner.
In Jumanji: The Next Level, Ruby Roundhouse is a Shameless Fanservice Girl, but Martha - who is forced to assume Ruby's identity as her avatar - fits this Trope better, mortified at having to wear Ruby's skimpy outfit and questioning why any sane woman would wear it in the jungle. Which is the whole point, as this plot element was done to lampoon the trend of scantily clad video game heroines.

Literature

Mercy Thompson is frequently naked, as when she changes shape, her clothes don't come with her.
Amelia Windrose from Orphans of Chaos, constantly. A climactic scene in the third book is enacted with her naked the entire time, and a villain standing between her and the only towel. It's...much more serious than it sounds.

Live Action TV

Teri Hatcher's character in Desperate Housewives often ended up in this kind of situation.
Justified in Primeval: Abby wears minimal clothing in her flat because she's deliberately keeping the temperature above 30 Celsius. Why? Well, she happens to be caring for a prehistoric reptile.

Newspaper Comics

Sally Forth from the U.S. Armed Forces newspaper (not the one seen in civilian Newspaper Comics sections).
Jane from the Daily Mirror strip of the same name. An urban legend claims that during World War II, when a rumor went out that D-Day would coincide with Jane appearing fully naked for the first time, army brass specifically asked the artist to make it so.

Tabletop Games

In the Scarred Lands setting, skimpy clothing is something of a requirement for arcane spellcasters, as such magic releases heat within the spellcaster's body, explaining the core rule systems ban on wizards using armor while also giving the caster the buff protection from cold with the side effect of making any heavy clothing really uncomfortable to wear. While there are many Shameless Fanservice Girls among them who embrace this requirement, their skimpy outfits made with the intent to draw attention to themselves, there are many who fit this trope too, who wear scant clothing under loose fitting robes that they can quickly cast aside when they need to use magic.

Video Games

Natalie in Epic Battle Fantasy, after using her Kyun Limit Break, will usually comment on it afterward by saying, "Well, that was embarrassing", "I hope that's enough fanservice for a while", and "Okay, stop staring now."
The women in Real Girls Strip Poker react this way after the (presumably male) player has stripped them nude.
Jill Valentine is this in the original version of Resident Evil 3: Nemesis. According to the novelization, the reason for the infamous tube top and short-shorts outfit is that her goal is to escape the city, not stay and defend it, so she figured she'd wear something that allowed freedom of movement. Of course, most fans know the real reason...

Web Comics

Elly from The Word Weary is the only female character to have been featured in a state of undress in the comic, much to her disappointment.

Web Original

The Nostalgia Critic. Although he's fine to give Fan Service on his own, if he's the victim in other videos (like the Game Heroes promo where they kidnapped him or Spooning With Spoony II) then he'll take on this role.

Western Animation

Seen briefly in a movie that Homer and Marge watch on The Simpsons, "The Erotic Adventures of Hercules".

Girl: Hercules, the Cyclops tore off my clothes!
Hercules: Ha-ha-ha-ha-ha!

Fluttershy from My Little Pony Friendship Is Magic becomes an in-universe example during her brief stint as a supermodel. She hated having the whole world stare at her, but the shy and embarrassed looks she gave to the camera were what got her discovered (in addition to her naturally being very graceful and beautiful). Also, even though ponies don't normally wear clothes, it was implied that some of the outfits she had to wear were chosen specifically to show off her body.
- In a second season episode she even seems embarrassed that Rainbow Dash caught her naked in bed, even though, as stated, the characters usually don't wear clothes.