Non-Nude Bathing

A character takes a shower or a bath without being naked or is shown in the bath or shower in their underwear, a swimsuit or regular clothes. This may happen during Bathtub Bonding between a man and a woman. Sometimes no-one seems to mention or even notice that the character is still clothed. Obvious reason: It's a heck of a lot easier to film (for a PG rating!) than if the bather were nude. Frequently results when a Digital Bikini is added to edited anime.

Examples of Non-Nude Bathing include:

Anime and Manga

Ikuto insists on this in Nagasarete Airantou when Suzu wants to bathe with him, making her wear a towel the whole time.
Pretty much any anime based on a Ken Akamatsu manga. Seen mostly in Love Hina, but it pops up in the Negima anime a few times as well.
Misaki and Usagi take a shower while fully clothed toward the end of the second season of Junjou Romantica. Season two was generally less explicit than season one anyway.
Galaxy Angel Rune's Hot Springs Episode... at least until the Transvestite dorm manager shows up with just a towel and yells at them for going it wrong.
Ranma ½:
- In the "Bathhouse Battle" chapter/episode, Happôsai wages a desperate battle with Ranma to breach the women's side of a public bath house only to discover Nabiki Invoked this and the girls are wearing bathing suits (a sensible precaution, knowing Happôsai). Note that the traditional Japanese bathing practice of washing before you soak in the tub doesn't require one to be nude in the tub itself.
  - It's actually zigzagged all over the place in that episode. At first, most of the girls are naked, including the named characters, as seen when Akane and Nabiki look over the wall. Then, when Happosai finally gets over to the girls' side (and gets Ranma out of his hair momentarily), most of the random girls in the background are unclothed but Akane has donned her swimsuit, as have Nabiki and her unnamed friends. Then, later when Happosai is using Bathhouse-Fu to knock Ranma around, Akane invokes an in-universe Double Subversion on Happosai by loudly calling that it must be safe to take their suits off (although the trick is pretty obvious to the audience).
- Later on, when (due to a misunderstanding about Ranma's masculinity) the family has to convince Ranma's mother Nodoka that he is man enough to want to peek at naked girls in the bath, they set up a whole production to give this impression. There were even strategically-placed soap suds and bubbles as Akane bathed. But when Ranma accidentally barged in (instead of peeking from the door like he was supposed to) and Akane got out of the tub, it turned out she was wearing a strapless one-piece and—this being a black and white manga—the soap suds only gave the impression she was naked.
The ending credits to Seikon no Qwaser shows all the main female characters in a bathtub filled with water but with their clothes soaking wet and on them.
Rouge from Sonic X is shown taking a bubble bath with her gloves on.
Detective Conan: Ran and Conan wear bathing suits in public baths.
Haré+Guu has a whole episode based on this, after Guu gives Haré the idea that bathing with your clothes on is the newest fad. Haré is just Genre Savvy enough not to take Guu at her word, but his attempts to debunk her story only confirm it thanks to Contrived Coincidences in which Haré visits people just as a washing machine overflows or they're cleaning the bathroom. On a trip to the jungle hot springs, Haré tries to put the fad into practice and gets laughed at. He tries bathing naked only that time he realizes too late he got into the public pool area.

Comic Books

In the XXXenophile story "The Spirit Is Willing", the spirit of a girl who died in the shower notes that the male hero still wears his shorts, and she asks whether he always does so. Apparently not.

Film

Done by Ed in Good Burger... because he never takes his Good Burger uniform off.
Weird Science: After creating the perfect woman, two nerds take a shower with her. She's naked, but they keep their jeans and socks on.
The Sting: When Hooker arrives at Gondorff's home, he finds him sleeping off his drunkenness. He puts Gondorff in a shower fully clothed to sober him up.
In the horror film Sick Nurses, one of the nurses takes a shower fully clothed. Evidently, the makers of this film really wanted to avoid nudity.
Cary Grant does it in Charade.
Winona Ryder does this in Heathers, in the girls' shower.
Winona Ryder also is seen doing this in Girl, Interrupted. She was thrown into a bathtub with her clothes still on to wake her up.
The kid in Big Daddy. Likely to eliminate any very Unfortunate Implications of Adam Sandler bathing a little kid. Lampshaded: The child asks why he has to wear a bathing suit, and Sandler responds that he doesn't know the rules for bathing.
Dr. Gonzo from Fear and Loathing in Las Vegas does this during a bad acid trip. In a tub full of filthy, brown water.
Rock and Roll High School: Riff is fantasizing about the Ramones serenading her in her room. She goes to take a bath and is delighted to find Dee Dee fully clothed under the shower.
In Courage Mountain, Heidi is upbraided by the school's teachers for not doing this.
Justified in the Sophia Copola film Marie Antoinette in which the eponymous Queen bathes in muslin undergarments, which is historically accurate.
Originally, Monty Python and the Holy Grail‍'‍s bathing scene in Castle Anthrax would have had the girls naked - but that would have prevented the film from being aired on television before the watershed. Then they realized that they could have the girls wearing shifts... and leaving something to the imagination meant that the scene became even more sexually charged than it would have been with full nudity.

Live-Action TV

In the first regular episode of The Ropers, Stanley thankfully leaves on his bathrobe as he tests his bubble bath water temperature.
Arrested Development: Tobias Funke is a NeverNude, so he wears denim cutoffs in the shower.
The 2006 series of Robin Hood did this and Lampshaded it where Much gets a servant girl:

Much: You could take a bath? (she begins undressing) I meant pour your own bath! And wear a bath-shirt!

Scrubs:

J.D.: Shower shorts. For the man who has nothing to hide, but still wants to.

Star Trek
- Episode "The Naked Time" of the original series: when a group of people are infected with an insanity-causing substance, one of them freezes to death while taking a shower with his clothes on.
- This happens again in the second episode of Star Trek: The Next Generation. No surprise, as it was an updated version of the above.
In Martial Law when the Buddy Cops go undercover in prison, the black cop goes to the shower in shorts and shirt in fear of Prison Rape.
On Baywatch, the lifeguards keep their bathing suits on when they hit the showers.
- partially justified in that lifeguards will usually enter the showers in their suits to rinse the salt and sand off, but take them off in mid-shower to what the suit covers.
In an episode of M*A*S*H, Hawkeye is so exhausted after a marathon surgery session that he doesn't bother to disrobe before taking a shower.

Video Games

The Sims
- The Sims 3: Sims with the Never Nude trait are, well, exactly what you'd expect.
- In the iPod port of Sims games, everyone is a Non-Nude Bather.
Grand Theft Auto Vice City: On the VCPR Radio station, a over-protective mother states "My kids know when it's bath time to put on a bathing costume, Nudity leads to Bad, NAUGHTY things."
In Fahrenheit (2005 video game) you can have any of the three main characters take a shower at some point in the gamer. However, they do so while wearing their underwear. This is only in the American version though.
In Animal Crossing, villagers of the "lazy" type will sometimes complain that they don't have any clothes to take a bath in, and asks the player for some.
In Rune Factory 3, everyone wears their swimsuits to the bathhouse.
In Final Fantasy X-2, whoever visits the Mt. Gagazet hot springs does so either in swimsuits, or in their regular NPC clothes.
Slightly Averted in Tales of Symphonia, if the characters are taken to the hot springs they aren't wearing anything except for a towel. Still though doesn't explain why they are wearing the towel at all in a bath.
In Pokémon Ruby, Sapphire and Emerald, the player character can get into the Hot Spring in Lavaridge Town while still fully clothed.
You can visit a bath house in the Shantae, where she jumps in clothed.

Western Animation

In George of the Jungle, Maggie simply jumps into a bathtub still wearing her clothes.
In The Simpsons, Flanders wears a bathing suit in the bathtub. When Homer asks why, he responds "So I don't see my own shrinky-dink." (Homer, slowly: "...Makes sense.")
In Ed, Edd 'n' Eddy, whenever we see Eddy showering for any reason, he's wearing his underwear or swimming trunks. The fact that he was physically abused by his older brother for most of his life edges this into Fridge Horror.
On the Looney Tunes short "Hare Tonic", Elmer Fudd rushes into the shower when he thinks he has contracted "the dread disease Rabititus" from Bugs Bunny. The gag is that Bugs is in the shower as well, pretending to be the faucet, but what's also funny is that Elmer still has his briefs on.
In the Kim Possible episode "Rappin' Drakken", a guinea-pig henchman takes a shower in his boxer shorts while testing "Dr. D's BrainWashing Shampoo and Cranium Rinse".
In the Rugrats episode "Naked Tommy" , Tommy and Chuckie are in the bathtub, and having spent nearly the entire episode naked, Tommy is shown to have changed his ways by wearing his diaper and t-shirt.
In the All Grown Up! episode "Tweenage Tycoons", Dill wears a swimming trunks in the bath (although this could be because he let his pet goldfish bathe with him)
In episodes on the Muppet Babies where any of the characters are bathing, it's *always* with a swimsuit. Considering the characters are juveniles, it's justified.
There is a scene in She-Ra and the Princesses of Power where Mermista is sulking in a bubble bath binging on ice cream, wearing the same outfit she always does. Of course, she is a mermaid and can swim easily in the same outfit, so she likely saw no problem there.

Real Life

This is true of public hot tubs (or indeed any hot tub) where the intention is to soak and not bathe.
This is normal in some public showers.
Truthfully, this Trope could once be applied to swimsuits in general and shifts in cultural norms. Before the 18th Century, people rarely wore anything for recreational swimming, but around that time, men and women started to go to public beaches together, and decency-inspired taboos and laws started to be adapted.