The act of drawing a female character with unusually large and buoyant breasts and without a bra, then animating every individual jiggle, sway, bounce and bobble they undergo. Also known as Gainax Bounce or the Gainax Bounce Effect.
The motion so displayed is typically asynchronous — each breast is animated separately and possesses its own individual movement.
The term was coined by fans some time before 1993 and makes reference to the anime production Studio Gainax, many of whose earlier releases made use of this particular variety of fanservice. According to a Usenet post from 1993, one particular busty young woman from the Gainax anime Otaku no Video inspired a tongue-in-cheek unit of measurement for Gainaxing: one full bounce is apparently equal to one "Misty May".
When a male character does it, it's a Pec Flex.
For a live action TV series built around this trope, see Jiggle Show. For real-time generation of jiggling movement in videogames see Jiggle Physics.
Do not confuse this with a Gainax Ending - there it's the individual parts of the viewer's brain that gets contorted in different directions.
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Bizarrely, advertisements for the UK insurance comparison website "Confused.com" do this very often, such as in this,this,this, and this advert. And yes, they do get weirder and more overt each time. Especially odd because the main character evolved from a head-and-shoulders mascot with no apparent gender whatsoever.
Cowboy Bebop has the character Faye Valentine, who is breathtakingly beautiful with gigantic pneumatic breasts that seem to have minds of their own. Canon indicates that she does this on purpose to distract men. On one occasion, she wears a perfectly normal evening gown.
The seventh One Piece movie had the girls bounce from doing absolutely anything. Hell, in a few scenes, Nami will simply be standing around, perfectly still, and her boobs will just randomly bounce quite forcefully all on their own.
Perhaps ironically, Gunbuster actually features what can be considered as close to realistic as possible physics for the bouncing breasts. Noriko's bounced so much mainly because she moved around a lot even when she wasn't wearing a bra.
Just about any female character in the various Burn Up! animes.
Kurono Kurumu in Rosario + Vampire. The movement of her breasts even produces audible sounds! And in episode 4, Kurumu's fat stalker (or rather, his belly).
Chapter 95 of the manga Mx0 plays this trope for satire with a magical liquid that makes some (already extremely buxom) girls' breasts experience only 1/6 normal gravity. The result is a lot of bouncing, first from falling, then from wind, then an earthquake.
To Love-Ru seems overly fond of this. Espically Lala. Just watch the OVA opening, 1 minute and 30 seconds of pure bounce.
Every female character that appears in the various Ranma ½ motion pictures — even the ones who are supposed to be small-breasted. This contrasts with the main series where they never seem to move at all, since the show is kind of old and didn't have a huge budget.
Especially since the characters are considerably less endowed in the television series.
May be at least partly Creator Appeal, on the part of animation director Atsuko Nakajima, who was so infamous for drawing her characters this way in the mid-90s that it earned her the nickname "Knockerjima".
The sheer quantity of gainaxing found in the anime Plastic Little inspired ADV, the North American distributor/dub house, to include an on-screen "Jiggle Count" meter as one of the special features in their DVD release.
The anime Shinkon Gattai Godannar!! takes Gainaxing to the extreme, since even the mecha have breasts (and in one particular case, both the mecha and the pilot have humongous jiggling breasts). The only exception to this is Lou, the show's Token Mini-Moe.
Practically every female role in Divergence Eve and its follow-up. It may be noted that outside of this and the fanservicey opener and closer, the series is remarkably serious in tone and tells its story in blissful.
The title character in Amazing Nurse Nanako falls prey to this, making an otherwise well plotted series difficult to watch "◊"
While not exactly as flagrant, Murrue Ramius of Gundam SEED has the dubious honor of having her bouncing chest be one of the few whose bouncing was actually animated and used as Stock Footage every time the Archangel took a particularly nasty hit in battle. This seemed to be limited to her, until first officer Natarle Badguirel ended up in command of her own ship, whereupon she gained the suddenly bouncing breasts (albeit not as dramatically given her modest proportions), as did Flay Alster as part of her crew. Whether this is actually an accurate depiction of how breasts move in zero gravity is debatable.
Murrue was also the first woman in the Gundam franchise to have her jiggle in the opening credits of the actual series itself. She was replaced in the HD Remaster by Fllay Alster. The James Bond opening credits level nudity is also bra-less and even had male viewers often going "...those don't work that way." Female tropers, on the other hand, winced in pain and often skipped those credits.
"They wounded the burst-proof battleship in order to sway the heart of the captain." - Moetan II, volume 1 (the book). Obviously, the word "heart" in the Japanese translation can also mean "breasts".
Yoko, and Kittan's three sisters (who come in small, medium and large for your viewing pleasure) in Tengen Toppa Gurren Lagann. Guess who it's made by. In fact, the English trailer for Gurren Lagann contained the words "that famous Gainax bounce". Yoko is an especially amusing example because her breasts seem to spontaneously Gainax without any movement on her part, whenever any attention is called to them.
It almost got her killed once, her rack sprang back into shape after being pressed against a wall, nearly launching her over a cliff.
Angela, an American visitor to Genshiken, displays this conspicuously (complete with bouncing sound effects) to make the differences between Japan and America (or at least Eagleland) more obvious, and to highlight her more upfront attitudes about sex (she is an unashamed Yaoi Fangirl) and maybe a bisexual (she was at least interested in the male oriented hentai as well).
Oono also gets this quite often.
A certain animation team in the rotation for Digimon Savers used this technique on Rosemon, and it's probably not a coincidence that they animated BioLotusmon's only appearance.
It's worth noting that before Savers, the only minor use of this trope was in the second Tamers movie — Sakuyamon's bounce a bit when she's freed from a Parasimon tentacle.
Digimon Xros Wars has Lilithmon and her boobs (she even fondles with them), and then there's Mervamon for the good guys (the opening even has her boobs bounce!), who even fires lasers from her breasts.
Siesta is nothing compared to Tiffania, who barely has to move to set her breasts bouncing around like Flubber.
Used to great hilarity in one episode when the gang is trapped in a cave. They hear something approaching fast and prepare for a fight, until Saito realizes exactly what that sound is with a priceless look on his face while the viewers get the obligatory chest shot of the approaching Siesta (who's wearing the Sailor Fuku outfit Saito bought earlier).
Mai from Mai-HiME dresses conservatively, but her somewhat large (but not Gag Boobs-level) chest still has a bit of bounce to it. A scene early in the anime replicated during an argument with Yuuichi and Shiho gives them an audible "boing". According to supplemental materials, it's not even Mai who has the largest bustline. She's beaten out ever-so-slightly by Haruka, who doesn't have a whole lot of bounce, but still looks good in a swimsuit.
Strangely enough, while attention is frequently called to her lack of a chest in the original series, Arika in Mai-Otome Zwei starts bouncing quite noticeably, especially whenever she prepares to use her signature move. One could argue, though, that she has filled out in the one year since the end of the series.
Macross Frontier features a whole raft of characters with sufficiently Gainaxed breasts, including Sheryl and the Miss Macross Frontier contestants (which makes Ranka uncomfortable.) Also, zero gravity bouncing. Very unique.
Interestingly the show also subverts the trope slightly: when a fully sized, thirty-foot-tall Zentraedi, Klan Klein has a rather terrifying bust that may actually be capable of killing a normal-sized human. Micronized, however, she doesn't possess anything that can be Gainaxed.
R.O.D. TV had one particularly infamous chase sequence where Nenene finally finds her long lost friend (love?) Yomiko Readman. Yomiko runs away and Nenene gives chase. As they sprint, their bosoms (which had been largely still until then) bounce and sway like jello earthquakes. It's also worth noting that Yomiko's bustline went from a mild C-Cup in the OVA well into DD territory for the TV series, set several years later. A late blooming?
It isn't just the chase scene. Watch Nenene's bosom in the first episode. They ripple like water.
This happens to Milly and Shirley during one of the School Festival activity episodes in Code Geass and to Kallen, the most noticeable example being her encounter with Suzaku on Kamine Island. You'd think that Kallen, having one of the larger chests of the female characters featured on the show as well as being the most physical girl, would get a lot more of this during the action sequences but the total count reaches no more than a handful.
Before the Time Skip, Arf displayed this trope whenever she got a chance to.
Fate got it from Precia.
If the video game is any indication, then Vivio's quite bouncy in her adult form as well.
Shockingly, despite having one of the larger bust sizes in the series, Signum doesn't bounce very often. She apparently prefers to show some leg.
Surprisingly, several girls in the Saiyuki anime jiggle around in action, even though the show is mostly fangirl fodder.
Then again, Saiyuki was originally marketed as Shōnen.
Done poorly with Bekira in Wagaya no Oinari-sama. Kind of lampshaded by Noboru taking a quick glance at Kou's assets for comparison. Subverted later on when it turns out those weren't actually her breasts.
Parodied and lampshaded in an anime-original RPG Episode of Hayate the Combat Butler where the bouncing boobs of the RPG game's boss is focused on constantly and has a sound so audible a character points out that she hears the sound of the bouncing from a considerable distance away.
In Akane-iro ni Somaru Saka's eighth episode, whenever the camera focuses on Tsukasa, her breasts appear to take on a life of their own. The first scene, which is just a profile shot of her laughing, has them bouncing up and down like crazy.
In one episode of Naruto, the seriousness of Gaara transforming is lost thanks to Temari's inexplicable Gainaxing, which is something that no character in the show had really shown before or since (even Tsunade, who despite having a bustline greater than a meter, no bra, and a very active combat style, has her breasts remain perfectly stable).
It appears as though you haven't seen 106cm  (bad quality)
Rosette does this in the third episode of Chrono Crusade — unfortunately bad animation makes it look as if she had bags filled with water instead of breasts.
Done with refreshing realism in Gargoyle of the Yoshinagas. A character's breasts do bounce but only after another character steals her bra.
Yurika in Akikan! actually uses Gainaxing as a strategy. In a baseball game with Yell (who's distracted by moving objects), she apparently plays without a bra on purpose, leading to very springy bouncing that Yell just can't take her eyes off of.
The baseball episode has a ninja distracting himself by imagining Kaede in a tiny bikini, complete with bouncing. The real Kaede bowls him over because he's not paying attention.
Parodied in Samurai Champloo when small-chested Fuu decides to carry a couple of cherry bombs by sticking them down the front of her kimono. And then she goes for a run. The result is quite comical, which is compounded by the occasional viewer who didn't notice the cherry bomb thing and thinks that her breasts have just gone insane.
The appropriately-named Bouncy Tiff, who is created to the real Tiff's dismay. She is drawn like a stereotypical magical girl and... err, deserves the "bouncy" portion of her name. Even the youngest character in the crew knows to cover his eyes. The anime she appears in? Kirby of the Stars.
Miyuki in Basquash!, who has her bouncing breasts take up the entire screen for a good few seconds.
Which is taken to the next level with Haruka Gracia, who we get to see jiggle on three separate occasions before actually seeing her face.
The SHUFFLE! OVA had Sia and Asa Gainax within the first three minutes. Then when Sia's dad replaces the water in the pool with eels, Nerine does as well.
The anime of Umineko no Naku Koro ni gave most of the women and girls a bad tendency to do this, which would be fine if this were a comedy series. Unfortunately, Umineko isnotacomedy series. Poor Shannon has the worst of it. Every time she makes a sudden movement or reacts to something, her boobs also react, with a single bounce.
In Bleach, Rangiku's breasts bounce when she is frightened by Capt. Hitsugaya's intrusion. She even says that they almost popped out of her robe.
When Orihime was about to change (in front of Uryu, uncaringly), her breasts just flopped down from her shirt. In the video games, she demonstrates this as well.
Even one of the more serene shows, Umi Monogatari, gets a chance to indulge in this trope. Oshima, Kanon's rival, is flaunting her own bust size, when Marin comes running up to greet her. Marin, already halfway to being an Innocent Fanservice Girl, is not wearing a bra. The results leave Oshima stunned.
Nodoka of Saki says hi. Just the simple act of walking could get her breasts jiggling.
A critic from Anime News Network once noticed that her entire wardrobe is sewn in just the right way for her shirts to perfectly cup her chest.
This happens in episode 19 of Fullmetal Alchemist: Brotherhood; for unexplainable reasons beyond pointing out that Havoc likes big boobs, Lust's boobs bounce considerably.
Mii in Jungle de Ikou! Gainaxes quite a bit, thanks in part to her huge rack (Mii's breasts are supposed to represent Earth's life-giving energy); this is taken to a somewhat absurd level when Mii uses her powers to turn into a giant.
Another Studio Gainax creation, Neon Genesis Evangelion, would always promise "more fanservice" in the next episode. Strangely, this was the one time Studio Gainax didn't follow this trope: the show did have a fair amount of tongue-in-cheek fanservice, but its overall animation style was less "cartoony" and trying to be photo-realistic, so unrealistic "breasts bouncing around like water balloons" didn't really happen that often.
Mari puts on her new plugsuit and comments how comfortable it is, demonstrating how well it can support her relatively huge chest. It was relatively realistic, tough. And she was wearing skin-tight, elastic clothing at that time.
Also seen at two moments later in the movie, when destruction of the bones guarding an angel's core caused its chest to lose its tautness, resulting in a bounce of building-sized breasts; and when a naked Rei gasped in surprise.
In 3.0 a fairly serious scene becomes a little less so when it cuts to Mari's breasts bouncing excessively from the impact of her Eva's running footsteps.
Ladies Versus Butlers! is full of this, having ample fanservice moments. Sernia Iori Flameheart in particular, she even gets the sound effects, generally the other girls don't.
Golden Boy did this quite a bit, especially in the first episode (from the owner of a computer software company).
Queen's Blade has this by the truckloads but episode nine of the first season is most appropriate example being a Cattleya centric episode
Airmaster Mina has plenty of this but she's a Subversion of Ms. Fanservice and her figure is played mostly for laughs as her breasts tend to bounce out of sync with the rest of her body and the movements are extremely exaggerated
Chu's entire entourage in Mouse, even the flat chested one.
Done hilariously in the Beach Episode of Tokimeki Memorial Only Love with swimming team captain Koayu Utsumi, whose Gag Boobs jiggle just from her merely looking around, complete with sound effects (and it doesn't help that it's getting all the attention of all the guys around, which she hates so much, and especially since she's on lifeguard duty at the time).
Happens at one time or another to most of the female cast of the anime releases of the Koihime†Musou franchise who have large breasts, especially to Kannu. Ryuubi even gets to do it on purpose later in the series to lure someone into a trap.
In chapter 117 of Black Cat, one panel has Saya Minatsuki dodging Creed's slashes, causing her breasts to swing in visibly different directions. She's far from the bounciest female in the series, but she does seem like the kind of girl that would go without a bra in the comfort of her own home (which is where she was when that asshole Creed barged in on her).
Yuriko deliberately does this to Daichi while on the train in episode 6 of Kotoura-san. He ignores it, much to her frustration.
In the anime of The Ambition Of Oda Nobuna Katsuie has quite a bit of bounce to her breasts. Even wearing a solid steel breastplate doesn't stop her gainaxing.
Louise Fróis also displays this.
Sakura Trick does that on Haruka's self-declared D-cups. Kotone sometimes has this treatment.
Played for Fan Disservice in Berserk with Casca, as the only time we see this happen is during her rape by Femto, where the gainaxing actually serves to show how violently she's being assaulted.
Kill la Kill has this with Ryuko and Satsuki, especially during their transformation sequences.
Aachi and Ssipak has a female character that does this throughout the movie to hilarious effect. At one point, she somehow manages to find herself strapped to a motorcycle, riding on her rack, while bouncing down some stairs.
A truly groan-worthy live action example in Transformers: Revenge of the Fallen, in which Mikaela (played by Megan Fox) bounces like Pamela Anderson on Baywatch in Michael Bay slow-motion in what is supposed to be a dead-serious escape sequence. However, given that the entire sequence is in slow motion, she is running for her life, and they only had one take, it's somewhat more understandable.
One of the Lara Croft: Tomb Raider movies had a particularly glaring example even for them, where Lara runs (in slow motion of course) at full pelt resulting in a lot of movement that looked like it would be quite painful really.
That would be the first one. It looks like it ought to violate the laws of physics and biology, probably a result of the decision to enhance Angelina Jolie's breasts.
Word of God states that the only part of Angelina Jolie that actually had any padding at all while filming was her breasts.
There are a couple of noteworthy sex scenes in Cabin Fever prominently featuring Cerina Vincent's breasts. But in particular, the second one involves a behind-the-back shot in which we can see an intense jiggle as she forcefully rides her lover du jour.
In The Legend of Zorro, there's a scene where Catherine Zeta-Jones runs away from dogs in a low-cut dress. It's probably not intentional, given the shortness of the scene.
Epic Movie does this with three different jogging people:
The first one is a scantily-clad woman.
The second one is a shirtless man whose Gag Penis bounces.
And in a moment of Fan Disservice, the third one is a fat hairy shirtless man with bouncing man-boobs.
Scarlett Johansson in her opening fight scene in The Avengers. Justified in that she's wearing a black cocktail dress which is not intended for the gymnastic martial arts moves she's using. Her Black Widow Spy Catsuit keeps her more... restrained.
Probably the most horrifying instance of this is in the 2000 sequel to the Eddie Murphy remake of The Nutty Professor, with Granny Klump.
In Monty Python's The Meaning of Life, Arthur Jarrett is allowed to choose the manner in which he is executed. He chooses to be chased off a sea cliff by ten voluptuos women who are wearing sneakers, knee-pads, bikini bottoms and helmets. Cue slow motion chase scene Made even more funny because Arthur is played by Graham Chapman, who was gay.
Linda Blair has a scene like this in The Exorcist Part II, The Heretic. She's tap-dancing (badly) in a school recital in a very low-cut costume. All anyone remembers from that scene is the fact that she badly needs a bra.
There is an interesting description of this happening to Big Boobied-Bertha in one of the How to Train Your Dragon books.
Live Action TV
Happy Endings has a classic example in 'Secrets and Limos', Dave's Girlof The Week comes into Jane's house, takes her coat off and just does a little shimmy to get out of it, setting her mams a wobble. It is clearly noticed by both Brad and Jane
Elaine on Ally McBeal invented a vibrating bra that would make the wearer's breasts twirl in circles.
The Bill — a couple of incidents described as "Bouncy Bouncy Jo Masters".
BBC Garden-show hostess Charlie Dimmock received a certain degree of fame for her tendency to go braless and jiggle.
So, forty years ago, did children's TV host Susan Stranks.
Baywatch. Kind of a given, what with the cast containing so many gorgeous women in form-fitting swimsuits.
This is the reason why Chandler and Joey from Friends love the show. In "The One Where Eddie Moves In":
Joey: Hey, hey, they're running!
Chandler: See, this is the brilliance of the show. I say always keep them running. All the time, running. Run! Run Yasmine, run like the wind!
Played for Laughs in memorable and very intended scene in the second paintball episode of Community, which shows Annie running in slow motion with a rather noticeable cleavage.
Earlier in the same season, Troy and Abed are Distracted by the Sexy due to Annie's Gainaxing…while she's yelling at them about being treated as a sex object.
Long before Pam Anderson hit the beach, Lynda Carter perfected the art of running in slow-motion in a bustier in the 70s Wonder Woman TV series. There is a reason why some say "the Baywatch run" was invented by this series. Observe
Actually, most of the women (who weren't flat-chested like Marcy or fat like the many customers in Al's shoe store) on Married... with Children gainaxed, from Peggy Bundy to the many shallow love interests Bud tried to score with.
My Name Is Earl had Catalina's stripper act entirely just jumping up and down. Another episode featured a claymation Joy whose breasts moved independently of each other, much to Randy's fascination.
This also often happened to Chrissy Snow from Three's Company whenever she got excited, resulting in the coinage of the term "Jiggle Show".
Ghost Whisperer has taken numerous opportunities to have Jennifer Love Hewitt run in something low-cut. In fact she seems to find a way to introduce some jiggle to every project she's in, including the bra ads.
Rachel Luttrell as Tayla Emmagan in Stargate Atlantis used to be known for this. Even in fight scenes. Especially in fight scenes! One director had her stop swinging a staff and * pose* in order to display her impressive chest to best effect.
On one episode of Dancing with the Stars, contestant Kelly Monaco was arguing with her partner, Val. She was trying to tell him how much Gainaxing occurs (and how uncomfortable it is) when you're doing the very bouncy quickstep when you actually have a set of breasts. To prove her point, she bought a bra, put a water balloon in each cup, put it on Val, and forced him to do the dance again. He got the picture.
It is the life's work of the protagonists of the reality show Double Divas to avert this. They make sure that all their customers leave with well fitting bras.
In Agents of S.H.I.E.L.D.'s "The Asset," a low-cut dress-wearing Skye makes her escape from villains by leaping out of a window into a pool, swimming out and making a run for it. Cue the Gainaxing.
In Baywatch, the Match Sequence has the camera pan down a line of female Baywatch lifeguards wearing sexy swimsuits. An operator configuration enables jiggling breasts.
Stand Up Comedy
Parodied by Bill Hicks on his Rant in E-Minor album:
I said, ‘I’d like to do a show where I rid the world of all the fevered egos that are tainting our collective unconscious,’ and the guy at CBS said, ‘Will there be titty?’ And I said, ‘Sure, I dunno, sure.’ BOOM! A check falls in my lap and... I'm a producer. I never knew it was that easy. All this time I've been trying to write scripts and characters and plots and stories that had meaning... “Will there be titty?’ ‘Sure.’ Boom, I'm a producer now.
‘Where have you been all your life boy, we've been looking for you in Hollywood. What’re these titties gonna do?’
BOOM! Another check falls in my lap. ‘You’re a fuckin’ genius. Give him another check. I can’t write enough checks for you. You’ve answered our prayers in Hollywood. Jigglin’ titties! Who woulda thunk of it?’
Rayne, the main character of the Bloodrayne series of games, and most of the other female characters in it, was notorious for it and noted by the media several times for its 'realistic' breast physics.
Though Rayne's breasts are immobile while speaking except for the first half second of every line when they bounce exaggeratedly.
Mai Shiranui from the Fatal Fury and King of Fighters series. The Fatal Fury anime movie, in particular, was infamous for the animators actually showing (very, very briefly) the inevitable wardrobe malfunctions her Gainaxing would cause in her distinctive costume during fight scenes. Viz Video, who released Fatal Fury in the U.S., used to show her bouncing in the trailers while the narrator made enthusiastic reference to "dual-independent-suspension ninja girl Mai Shiranui". Although her design in the first few games was relatively more conservative, the anime (and the 2D Jiggle Physics in the King of Fighters videogames) resulted in her Flanderization into a walking incarnation of this trope. In fact, the latest incarnation of the King of Fighters takes this to Serial Escalation levels.
Even in the Neo Geo Pocket games where she appears her breasts jiggle!
Soul Calibur III's shop girls, specifically what could be done by repeatedly hitting Triangle in their shops. Especially Valeria's.
Giving Xiangua's style to a well endowed custom character in Soul Calibur IV will result in lots of bouncing
Quite noticeable in Soul Caliber Legends, namely Ivy. Every movement made them bounce with really weird physics, including going in and out(...?)
If any character is the Soul Calibur shining example of jiggle physics, it's definitely Taki.
Rouge the Bat, from the Sonic the Hedgehog series, although this has been toned down in newer games.
Dead or AliveXtreme Beach Volleyball. The breast movements were synchronous until Dead or Alive Xtreme 2, when they consequently lost any resemblance to actual bosoms.
The first game even gave the option of choosing between static, semi-normal, and downright comical Jiggle Physics.
Tomb Raider's main character, Lara Croft, gets pretty jiggly.
Super Robot Wars, despite being a video game where all the action is done by Giant Robots, has rather extensive bouncing in the anime-ish cut-in pictures. Very prevalent in the Alpha series, where you can expect any original female character to have Gainaxing bounce, unless her name is Ibis Douglas. This also gets carried over to the latter handheld SRW games, such as J and W. (Un)fortunately, Super Robot Wars Original Generation somewhat mellowed or stopped this practice.
Only for Endless Frontier to bring it back in a grand fashion: 3 of the playable characters happily show off their bosom every time you perform their Limit Break (two of them involving a mechanism specifically designed to remove the cloth covering their cleavage), and most female bosses are happy to do this as well.
Funnily enough, even Xiaomu, from Namco X Capcom has what little cleavage she has bounce. In fact, every female character with the exception of Suzuka and Kyon Feulion have bouncy breasts.
It starts at Alpha 2 and Alpha 3 had the most extreme version of this (I'm looking at you Selena Recital). After that, the bounce is a bit more in line with realism. By Z, the bounce is fairly tame and looks fairly natural (which is impressive given Xine's impressive rack).
Tales of Symphonia played with this with the well-endowed (but not shockingly so) female ninja Sheena. However, it's only most noticeable when using her as the party avatar walking around, and it's hard to spot normally (there are a couple of places where you can get a closer look and have her run in place). It's also present in the animated ending cutscreen on Martel, the credits credit Gainax themselves for said animation.
Queen Valentina from the original Super Mario RPG had a conspicuously long after-hit animation that consisted solely of her flinching and jiggling for a few seconds.
It's notable that the jiggling part lasts about 3 times longer than the flinch.
For that matter, Bellena has some impressive (though subtle) jiggle physics.
For a male example, you have Pinta's belly jiggles.
The really interesting bit is that your two female companions (and a vast majority of other female characters, including Piastol, an otherwise leather-clad dominatrix-looking type) do NOT have any jiggle physics to speak of. This implies that it isn't an artifact of the physics engine, but instead something that someone spent development time on simulating.
Fiona from Haunting Ground suffers this. Especially noticeable when you unlock some of her other very revealing outfits.
Nearly every female character that isn't flat chested in Disgaea.
World of Warcraft features Gainax physics in the ears of the elven races, though more prominently in the Night Elves than the Blood Elves. The Night Elf ears stick out to the side and are very large so the bounce is easy to see. The Blood Elf ears stand straight up and are smaller but bounce just as much.
Their boobs move around quite a lot too. But actually, the boobs that bounce around a lot in World of Warcraft are on female undead. Sort of justified as they probably aren't attached properly anymore.
They even have a /silly that implies that they were originally attachedto someone else. ("Yes, they're real. They're not mine, but they're real.")
Take a look at the female dwarf's running animation; it's almost hypnotic. But other then the Night Elves and Dwarfs, the jiggling is surprisingly realistic for a game.
The Pokémon Nidoqueen actually displays this in the Stadium games upon release and before executing a physical attack.
Blue-Eyes of Pokémon Ranger: Guardian Signs, despite being a tiny sprite, has visible Gainaxing when she does her Action Pose.
Kongiku from Muramasa: The Demon Blade has very large breasts that tend to wobble and jiggle constantly, even when she's not doing much other than standing there, breathing. The jiggle isn't as exaggerated as the most extreme examples of this trope, but is quite noticeable.
The priestess Rao in Ōkami jiggles wildly every time you meet her, including after she's possessed by the demon Ninetails. Issun rarely refers to her as anything but "busty babe", even to her face.
It's mentioned in the game's official art book that one of the programmers created a "bounce and sway program" with "great attention to detail" to get Rao's breasts to jiggle just right.
Zola in Blue Dragon. She's by far the better endowed of the two girls in your party(and it shows). So naturally, instead of a bra, she wears a blue tube top. Tube tops are not known for their supportive properties.
The female protagonist from Epic Battle Fantasy's breasts can be clicked on and they jiggle there's even an achievement for it
Every single game from Japanese H-game maker Illusion. Being strictly h-games they generally have controls that affect the size, shape, firmness, effects of gravity....
Surprisingly, somehow they seem to have averted (mostly) in their latest game which uses a different, much more realistic (for varying degrees of realistic) engine versus their traditional anime-esque style games. There is still bounce, but much less Gainaxey.
In one cutscene in Batman: Arkham Asylum, Batman tackles the newly Stripperiffic Harley Quinn by jumping on her through a pane of glass, causing her breasts to jiggle slightly.
Dr. Naomi in No More Heroes 2: Desperate Struggle has a preposterous bounce animation triggered when the player speaks to her in the laboratory. The self-awareness of this is heightened by Naomi's comment, 'Quit staring at me! I know what you're thinking— and NO!' a nod to the fact that she appears to have grown since the first game in the series and been put in an impossibly small top. It is a simply wonderful piece of Fanservice.
Ms. Fanservice Kasuga from Sengoku Basara previously never displayed this despite sporting some impressive Absolute Cleavage. However the latest game corrected this with subtle yet realistic bouncing, as did the anime series (where her breasts are much larger than normal and it was not all subtle).
Being based on the WWE, it's a given with the licensed games. It does get hilarious in one of the older PS2 games, when you encounter them in cutscenes and their breasts jiggle noticeably every time they revert to their default position between dialog lines.
Averted with Cloud of Darkness, since in Cutscenes she tends to glide slowly as she moves giving not enough momentum. But doesn't stop Laguna from staring regardless.
It's also in a few of FF7's cutscenes. Too bad it took until 10 for such physics to be in effect even in battle...
Gods Eater Burst has a small amount, but disturbingly, not for the human characters. Some female shape Aragami such as the Zygote, Sariel and Arda Nova Gainax quite a lot, most notably in Arda Nova's death closeup. Hell, one monster◊ has a rack that may very well be visible from space!
Selvaria of Valkyria Chronicles. Most of her major scenes focus either on her flaming blue badassity, or her.. um, "talents", and the jiggling is truly astounding when the camera's on them. One particularly dramatic scene suffers because of the focus on her breasts bouncing around in different directions.
Akatsuki Blitzkampf gives us Marilyn Sue, who's popular with fans both for her powerful, hard-hitting fighting style and for her huge, huge jugs that bounce and swing every which way as she smacks around her opponents.
The female Boss from Saints Row: The Third Can fit into this trope if you slide her sex appeal all the way to 100.
Dahlia in Duel Savior Destiny supposedly, though since her sprites are static we only have sound effects and Taiga's reactions to go on.
As of installment #13.5, Hopeless Masquerade, even Touhou has gotten in on the action. Although only one character actually bounces.
Shantae's boobs (and those of her female supporting cast) seem to get bouncier each time the graphics are updated. It's more realistic and less painful-looking than most other examples on the page, though.
The new physics engine used for animating season 2 of RWBY allowed them to add more realistic movement to things like cloth and hair, but with Yang in her new form-fitting outfit it takes on a much more glorious purpose.
One Gaia Online comic update shows Lex, Sasha, and Ruby jogging in anticipation of an Olympics-themed event. About half the fan-edits of said comic focus more on Ruby's bouncing jubblies than anywhere else.
Referenced in thisSkin Horse strip where a hacked game of Mario Kart is described (but not shown, tragically) as having Peach not wearing a shirt and having a "Gainax bounce".
Sahira's breasts bounce around rather notably in this Spinnerettecomic. Curiously, characters with even larger breasts such as Greta Gravity hardly gainax at all. Then again, Greta Gravity is a Gravity Master...
Inverted in Scandinavia and the World. Sister America's large (fake) breasts don't move at all. Apparently they're "like footballs glued to her chest".
Jessica Rabbit from Who Framed Roger Rabbit. Her breasts were purposely drawn to bounce in the opposite rhythm of a normal female's chest while walking; she bounces down when a real person would bounce up, and vice versa.
And they go "boing"!
In the 1937 Disney short Mickey's Amateurs, Clarabella Cow and Clara Cluck both have unusually large bust, jiggling to the rhythm of the music Clarabella plays on the piano.
Betty Boop was also known to do this in certain cartoons.
Hell, it's not even breasts, but Invader Zim got away with this through Zim's zit, aptly named "Pustulio".
Technically it was necessary though, as the whole jiggling thing gave the hypnotic effect it had.
Princess Vespa in G4's animated Spaceballs adaption is usually animated this way.
The animated short film, Loco Melones, shows two of the women's boobs bouncing.
The buxom old lady from Coraline bounces quite a bit, particularly when she shoves her sister out of the way using her breasts. The Fan Disservice levels are cranked up to eleven later on when she appears to be jumping on a diving board... naked.
Titania, a bartender from The Simpsons used this (combined with her natural talents) to her advantage in order to try and win the "Beer-Tender of the Year" contest. She loses when she refuses to throw out a drunk, telling Duffman that she slept with him to get out of participating in that part of the contest (Duffman's response: "Duffman says a lot of things! Oh, yeah!")
Like every female character, and some of the heftier guys, in this Confused.com commercial.
In the episode "Muscle Woman", both Starla AND Muscle Man get this a lot, effectively squickifying the episode.
The episode "Bald Spot" features Muscle Man gainaxing as a plot point. Specifically, he kept flexing his pecs (which translates in this case to jiggling his manboobs) throughout the entire episode in order to distract Starla from his bald spot on his head.
Avatar: The Last Airbender does small amounts of this with shadows. Rather than showing the actual breasts jiggling, the shadows do it instead. It can be quite hard to notice most of the time, and it's only very slight, but it's still something of a FanserviceParental Bonus
Averted in The Legend of Korra, however. Although Korra is a relatively busty young woman and her breasts do move around when she's in action, the "breast physics" are very realistic and not Gainaxish at all. It seems more like just part of the animators' meticulous attention to detail than any sort of fanservice.
SpongeBob SquarePants: In the episode "Party Pooper Pants", this happens to Minnie Mermaid at Patchy's party. Because this is live action, it is obviously more realistic than the rest of the examples in this folder.