[[quoteright:317:[[{{Shazam}} http://static.tvtropes.org/pmwiki/pub/images/CaptainMarvelIsntCardedAtClubs.jpg]]]]
[[caption-width-right:317:Don't trust him Billy! [[Website/SuperDickery Superman has an angle!]]]]
->"''Ta-ta-ta-ta-tata! [[ScoobyDoo Puberty power]]!''"
-->--Yugi Mutou during transformation, ''WebVideo/YuGiOhTheAbridgedSeries''

A trope closely tied with the MagicalGirl and some Western superheroes, this is a character with the ability to turn into a noticeably older counterpart of themselves. The most famous use is the "MagicIdolSinger", a pretty blatant piece of innocent wish fulfillment.

The wholesomeness of this idea is its main feature; that characters would run into rather {{squick}}y situations if they found boyfriends or girlfriends while changed is surprisingly common, and thus this trope is often combined with LovesMyAlterEgo.

Occasionally overlaps with SuperpoweredAlterEgo. Compare with DualAgeModes, OvernightAgeUp, SleepModeSize. When the change is more permanent, you have a PlotRelevantAgeUp.
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!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* Probably used first in the first ever MagicalGirl manga (though not the first anime - [[SallyTheWitch that was another show]]) ''Manga/HimitsuNoAkkoChan'', which first appeared in 1963. The CuteWitch female lead, Atsuko Kagami aka Akko, had a MagicMirror that allowed her to [[MasterOfDisguise take up the appearance of other people]]. Obviously, more than once she aged herself up to help the rest. In fact, she invoked the trope in the ''very'' first time she used her mirror by wishing to become "the Queen of the Stars" - the result was her becoming a beautiful older girl in a sparkly gown.
* ''Manga/MarvelousMelmo'' is another early MagicalGirl example, in which the 9-year-old heroine uses magic candies to age into an attractive 19-year-old PantyShot-tastic version of herself.
* ''Anime/MagicalAngelCreamyMami'' in which a young girl became an idol singer.
** Studio Pierrot would later use the same plot line in ''Anime/PersiaTheMagicFairy'', ''Anime/MagicalStarMagicalEmi'' and ''Anime/MagicalStageFancyLala''.
** [[Anime/MagicalPrincessMinkyMomo Minky Momo]] had a wand that likewise aged her from 8-ish to 18. It also gave her perfect skill with any career she named with the age-up.
* ''Anime/SailorMoon'' had a wand similar to Minky Momo, used several times in the first 10 or so episodes, and then was promptly forgotten about after the FillerArc in the second series.
** Likewise, Minako has a compact that serves the same purpose in ''Manga/CodenameSailorV.'' Since Usagi is an {{Expy}} of her it's not surprising.
* This was the premise of ''Manga/FullMoonOSagashite.'' In addition to Mitsuki going from 12 to 16, she also temporarily loses the throat cancer she has as a 12 year old which prevents her from singing loudly. And in order to properly disguise herself during her first transformation she dyes her hair blonde. After that it's just assumed that Takuto and Meroko include the dye when they transform her each time.
* In ''Manga/LoveHina'' Kaolla Su becomes older under the semi-mystical "red moon" and when her "big brother" visits.
* This seems to be Evangeline's power in ''Manga/MahouSenseiNegima''; however it's revealed that her "adult form" is just an illusion. Of course, it's [[PlayingWithATrope played around with]]... due to the fact that she's ReallySevenHundredYearsOld and stuck in her current form because [[OurVampiresAreDifferent she's a vampire]], Evangeline's illusion actually makes her appear ''younger'' than she really is... it's just her true form looks even younger than ''that''.
** Later in the manga "Age Changing Pills" start appearing, which are stated when introduced to just cast the same illusion Evangeline uses. Evidently, this illusion is fully tactile, extends or reduces actual reach and height, and doesn't cover your clothes (which can end up falling off or getting very tight).
* ''Anime/JungleDeIkou'', in which a young student gains the power to become a fertility goddess with the powers of Mother Earth in her breasts.
* ''Anime/YuGiOh'': When Yugi calls upon his mystical Millennium Puzzle to evoke the spirit of an ancient pharaoh into him, his voice deepens and he grows about a foot in height without raising comment from anyone. Since the cameo of the older Yugi in ''Anime/YuGiOhGX'' has him look largely the same, this is probably just a visual aid to the audience indicating his maturity. Mocked, as well as everything else, in the first episode of ''Yu-Gi-Oh: The Abridged Series'':
-->'''Seto''': Wait, did your testicles just drop in the last five seconds or something? What the ''heck'' happened to your voice?
** It should be noted, however, that this applies only to the [[Anime/YuGiOh second anime series]] ([[AdaptationDisplacement the one everybody knows about]]). In both the [[YuGiOhFirstAnimeSeries first series]] and the [[Manga/YuGiOh original manga]] Yugi stays the same height. His voice ''technically'' doesn't change, but [[SuperpoweredEvilSide Yami]] uses it with such confidence that he sounds completely different from [[ShrinkingViolet his other self]], to the point that it allows him to avoid being recognized by his friends in the first volumes of the manga.
* In ''Manga/ChronoCrusade'', Chrono is usually to be found in the form of a teenage boy. However, in his full demon form, when getting power from Rosette's seal, he is a fully grown and not-unattractive man.
* In ''Manga/TenjhoTenge'', Maya is usually portrayed as a really young girl, almost [[SuperDeformed chibified]]. It seems unlikely that such a child would be sword master; however, when she gets serious she transforms into well-endowed and shapely woman, capable of making members of the male species goggle. This is actually a reversal of the trope: The buxom beauty ''is'' Maya's true form. She regularly transforms into the tyke to conserve her strength.
* When schoolgirl sportscaster Tsukuda Miina becomes the Space Rabbit Girl Warrior Tsushiro Miina in ''Anime/GetsumenToHeikiMina'', she takes on a notably more... "mature" form.
* The last episode of ''ANime/DaiMahouTouge'' uses this as part of a power upgrade.
* Hono and Yuki from the ''MasterOfMosquiton'' OVA both have an adult form, which seems to be the form in which they can most effectively use their elemental powers. It's used as an excuse for blatant fanservice in the case of [[GagBoobs Yuki.]]
* The manga ''Manga/InstantTeenJustAddNuts'' is centered around this trope. In a terrifyingly creepy manner.
* ''Manga/AyashiNoCeres'' has an odd partial example--Aya's friend and fellow ten'nyo Chidori is in her late teens, but physically looks about ten. When she transforms into her ten'nyo form, however, she looks her actual age.
* Klein Klan in ''Anime/MacrossFrontier'' does this in reverse. At normal Zentradi size, she's a physically developed adult, but when Miclonised (shrunk to human size) she becomes a physical and mental preteen.
* [=ChaCha=] in ''Manga/AkazukinChacha'' can use the power of her brooch (and Riiya's bracelet, and Shine's ring) to turn into a "Magical Princess" who looks to be about 16 years old. She herself looks to be about 7-8.
* ''[[Anime/NanakaSixSeventeen Nanaka 6/17]]'' doesn't actually have this trope, however it is the explanation given to the main character after she suffers a severe brain injury that leaves her with no memories beyond the age of six.
** It actually ''does'' have this trope, but only in a minor capacity--[[ShowWithinAShow Magical Domiko]] does this when she uses her powers.
* In ''Manga/YuYuHakusho'', Koenma normally looks like a baby despite being ReallySevenHundredYearsOld. When in the human world, in order to be taken seriously, he appears in the form of a handsome young man... with a pacifier in his mouth. [[spoiler: He actually has a good reason to always carry the [[ArtifactOfDoom pacifier]].]]
* Both Jiyu and Freesia from ''Anime/{{Jubei-chan}}'' have adult alter-forms for serious butt-kicking.
* In the ''VideoGame/DevilMayCry 3'' manga, Alice (who resembles the protagonist from ''Literature/AliceInWonderland'') actually goes so far as to trade her innocence to demons for the sake of becoming older and more attractive.
* Vivio in ''Manga/MagicalGirlLyricalNanohaVivid''. If you've seen ''[=StrikerS=]'' [[spoiler:it's the same one she used in the final battle, though with less black in the Barrier Jacket]]. Like her mom, however, she takes a very responsible approach to life-altering magics and readily promises her to never use her adult form for fun and mischief. She also displays acute awareness of the fact that suddenly growing breasts doesn't actually make her an adult. Other characters also have a similar Adult Form, like Einhart Stratos, her [[TheRival rival]] [[ReincarnationRomance and maybe something more]].
** A villain example in ''Manga/MagicalRecordLyricalNanohaForce'': [[spoiler:Curren's child-like appearance in Chapter 29 may or may not her true form]].
* In ''Manga/FateKaleidLinerPrismaIllya'', Illya appears about 17 when she [[spoiler:becomes a Heroic Spirit]].
* Played straight with DarkMagicalGirl Pixy Misa in ''Anime/PrettySammy''. This is presumably a reflection of Misao wanting to be a daring, attractive grown-up. Meanwhile, the heroine Pretty Sammy is basically Sasami in a silly costume (the cast-offs of her {{Cloudcuckoolander}} sponsor). Sasami doesn't want to be someone else, being rather well-adjusted.
* Spoofed in a bonus manga chapter of ''Kodomo no Jikan'' that came with the 2nd OAV DVD. Poor Kuro remains flat-chested even in adult form, and poor Mimi gets even bigger.
* Aram of ''Manga/MeruPuri'' transforms from a 12 year old kid into a 17 year old teenager by coming in contact with darkness.
* There's a borderline example in ''Manga/{{DNAngel}}''--the main hook of the story is that Daisuke transforms into his alter-ego, Dark, when he experiences the feelings of being in love. Dark looks older and is much taller (to the point that Daisuke gets into the habit of wearing clothing that is too big for him). However, Dark is also presented as his own individual, who has appeared in the men of Daisuke's family for over four hundred years.
* When Ahiru transforms into Anime/PrincessTutu, she looks noticeably older, and also becomes several times more graceful, with a melodious voice and stunning dance skills.
* In ''Anime/{{Pokemon 3}}: Spell of the Unown'', Molly decides she'd like to be older, and they make it so.
* ''Anime/HimeChenOtogiChikkuIdolLilpri'' Being [[MagicIdolSinger magical idol singers]], this isn't surprising.
* In ''Anime/JungleWaItsumoHaleNochiGuu'', Guu can change into a beautiful young woman who is strong enough to defeat a bear.
* This is how Digivolving works in ''Anime/DigimonXrosWars'', as opposed to the usual EvolutionaryLevels.
* In ''Manhwa/DorothyOfOz'', Mara ages ten years and gains the powers of a witch whenever she uses the boots given to her by [[HotWitch Selluriah]]. Her hair also turns white and her eyes turn gold, for some reason.
* This happens in ''Anime/{{Beyblade}}'' of all things with BEGA member Ming-Ming who goes through some kind of magical girls transformation and like Yugi in ''Franchise/YuGiOh'' appears taller and has sharper eyes and slightly different hair. It's a very odd case as she was introduced in the later half of the last season. Notably, the small, cute Ming-Ming is the IdolSinger while the taller, sexy Ming-Ming is the Beyblader.
* Aguri Madoka from ''Anime/DokiDokiPrettyCure'' is a fourth-grader and her OlderAlterEgo is Cure Ace who is physically about Yuri/Cure Moonlight's age (17) from ''Anime/HeartcatchPrettyCure''. Aguri is the first and only Anime/PrettyCure with an OlderAlterEgo.
* Koneko from ''LightNovel/HighSchoolDXD'' has one in her Shirone mode, where she [[HeroicRROD overclocks]] her senjutsu; not only optimizing it's power but temporarily aging her to the body she will have once she matures to the point of saying that that will be the body she will have when she becomes Issei's bride. Unfortunately, [[AwesomeYetImpractical It's very exhausting to the point of being final sweeper attack]].
* Subverted cleverly in MagicKnightRayearth. [[spoiler: Princess Esmeraude is always seen in the form of a pre-tee/young teenager... but that's because her growth was stunted when she became the Pillar of Cephiro. Once Zagato is killed, [[BreakThecutie Esmeraude completely breaks]] and reverts to her ''actual'' age and form - that of a beautiful LadyOfWar who is [[LoveMakesyouEvil completely]] [[BrokenBird broken]] and a borderline OneWingedAngel.]]
[[/folder]]

[[folder:Comic Books]]
* The trope was formerly named, perhaps [[IAmNotShazam ironically]], after one of the exceedingly few western examples of it: DC comic hero [[{{Shazam}} Captain Marvel]]. The "awkward situations with adults of the opposite sex" was played straight with [[MeaningfulName Beautia Sivana]], but inverted in ''JusticeSocietyOfAmerica'' in which Captain Marvel reveals his identity to and begins dating a fellow superhero the same age as Billy Batson, and is later forced to break up with her due to misunderstandings from others who didn't know he was actually 16. His twin sister, Mary Marvel, has exactly the same power in some versions. (In the original Fawcett comics she gets the powers but doesn't age, like Captain Marvel Jr. In JeffSmith's ''Shazam and the Monster Society of Evil'' and Mike Kunkell's ''Billy Batson and the Magic of Shazam'', Mary doesn't get older and is also [[CuteBruiser noticeably younger than Billy]]).
** Becomes a plot point in ''ComicBook/YoungJustice'' when he is able to travel between all-kids and all-adults parallel worlds.
** Similar thing happened to his Creator/MalibuComics CaptainErsatz, Prime from ComicBook/TheUltraverse. He tried to use the older form to get together with a girl he had a crush on, which really creeped her out. Meanwhile, an adult heroine was nursing a crush on Prime.
* ComicBook/UltimateSpiderMan does this... sort of. He's actually 16, but usually tells people he's in his twenties when he's in costume. No one really buys it.
** Except [[DatingCatwoman Black Cat]], who had once kissed him. [[CrowningMomentOfFunny She threw up later when she found out he was really a kid]].
* ArchieComics Superhero ''[[http://en.wikipedia.org/wiki/The_Fly_(Archie_Comics) The Fly]]'' (also known as Fly Man) was originally one of these. Young orphan Tommy Troy was given a magic ring that allowed him to transform into an adult with insect-based powers. Unusually for this trope, the age differential didn't last. By the fifth issue Thomas Troy had aged a good ten years, gaining a law degree along the way, and was drained of any lingering trace of originality. (This was concurrent with the departure of the original Joe Simon/Jack Kirby creative team.) When The Fly and other Archie Comics heroes were revived under DC Comics' Impact imprint, this trope was re-established for the character.
* ''ComicBook/AmethystPrincessOfGemworld'' is another western comic book example. Because time passed at different speeds between Earth and Gemworld, she was older when she visited the other world. (Plus, of course, she had magical powers! And a flying horse!)
* ''ComicStrip/{{Bananaman}}'', people!
* A victim of the Scarecrow's experiments, an [[ConvenientlyAnOrphan orphan]] named Colin can willingly become the hulking vigilante Abuse (with reverse-embossed knuckle-dusters to match).
* Aside from Prime (see above), ComicBook/TheUltraverse also had Elven, a teenage girl who transformed into an adult female elf.
* ''Tod Holton, Super Green Beret''. [[http://www.misterkitty.org/extras/stupidcovers/stupidcomics36.html Check it out.]]
* As created by Mick Angelo, {{Marvelman}} originally had this, being a CaptainErsatz of Captain Marvel. When Creator/AlanMoore wrote the character, he had Micky Moran grown up.
* Inverted with Kevin Trueblood/Maximum Man in ''WelcomeToTranquility'', a CaptainErsatz of Captain Marvel who is now an old man, but, when he remembers his magic word, still turns into a thirty year old superhero.
* One arc of ''ComicBook/SupermanBatman'' had the titular duo encounter a team of expies of ComicBook/TheUltimates. The ComicBook/IncredibleHulk expy was a cute little girl who turned into a big blue monster.
* In ''Colt Noble and the Megalords'', an AffectionateParody of ''Franchise/MastersOfTheUniverse'', Colt Noble (the equivalent of He-Man) is the older alter-ego of the 13-or-so Prince Jaysen. The original one-shot starts with Jaysen fruitlessly trying to gain entry into a strip club, and ends with him enjoying himself at the club as Colt.
[[/folder]]

[[folder:Fan Fic]]
* This is one of the powers of the Grass Guardian in ''[[Fanfic/GuardiansOfPokemon Guardians of Pokémon]]''.
** Later, [[spoiler:Pikachu]] also gets the power to temporarily age up [[spoiler:using the Thunder Stone]]...but after the transformation has run out, she temporarily becomes even ''younger'' than usual.
* One particular Website/ThatGuyWithTheGlasses SlashFic casts [[WebVideo/AtopTheFourthWall Lewis Lovhaug]] as a high school student who uses a Franchise/PowerRangers transmorpher to become the superhero "Linkara". While the age difference isn't major, Linkara is stated to be five years older than teenaged Lewis (making him roughly Mr. Lovhaug's ''actual'' age).
[[/folder]]

[[folder:Literature]]
* In Creator/GeneWolfe's ''WizardKnight'' series, the hero is a young kid who is transformed into a brawny KnightInShiningArmor in a fantasy world but is still as naive as your typical KidHero.
* ''FlossieTeacakes'' - the 10-year-old main character finds a magical coat that magically transforms her into the young woman she dreams of being whenever she wears it.
* ''ComeOnOssie'' - Oswald turns into an 18-year-old when he borrows his grandfather's medal.
[[/folder]]

[[folder:Live Action TV]]
* In ''Series/OutOfThisWorld,'' Evie once turned herself into an adult, becoming "Evie's older cousin Yvette," to attract a boy. Attempts to reverse it rendered her seven years old.
* In ''{{Smallville}},'' an enchanted comic book turned a boy into an adult superhero. Chloe seemed semi-interested in him (with a FlightOfRomance, no less) until she found out he was really about ten years old. [[spoiler: Turns out, though, that the comic wasn't about a hero, but a villain's StartOfDarkness, and the kid was cursed to go AxCrazy the moment he felt betrayal.]]
* Justin in ''Series/PowerRangersTurbo'', mostly as a result of the suit-actor being the same age as the rest of the suit-actors, while the character actor was about [[DawsonCasting half the age of the other character actors]], with no actual in-story handwave. He even shifted back to twelve-year-old size when he removed his helmet. (We never saw that happen directly, sadly. When the Rangers would be suited but unhelmeted around the base, Justin would be wearing a kid-sized suit, all size-shifting happening offscreen.)
** This pertained not only to Power Rangers, but in Franchise/SuperSentai. Series/GoseiSentaiDairanger featured a 9-year-old that became the Kiba Ranger with the same circumstances. His living sword spoke for him while he was hiding his identity from the other Dairangers.
* The main characters of BigBadBeetleborgs are all kids who thanks to a Phantasm called Flabber [[AscendedFanboy become their favorite heroes]]. (Note the only the ''Dairanger'' example has to get around adult-sized heroes sounding like kids. Even people who know the kids and meet the heroes don't ever say a word about the voice thing.
* The titular character of ''{{Series/Merlin}}'' uses an aging spell now rather regularly to turn into an 80yr old version of himself, known as "Dragoon" most of the time, though Morgana may know him as Emrys due to her vision.
** And when Dragoon's compromised, he has Dolma, [[DisguisedInDrag a female]] OlderAlterEgo.
[[/folder]]

[[folder:Video Games]]
* ''Franchise/AceAttorney'': When channeling their dead sister/cousin Mia, Maya and Pearl Fey become vessels for her spirit. All this really means is that the full-sized Mia, bust and all, turns up wearing the younger Feys' clothes. It's bad enough when she turns up in Maya's body, but with Pearl, it gets downright {{Stripperiffic}}.
** This is actually ''invoked'' in one case, when Phoenix is trying to interrogate a witness who's a DirtyOldMan. To get the witness to talk, he brings in Maya, wearing a waitress outfit that the witness considers FetishFuel. The witness just takes one look at her and says for her to "come back when [she's] older". Cue her channeling Mia, and the witness starts talking immediately.
* [[spoiler:Johnny Garland]] from ''ShadowHearts: From The New World''. His actual age is... complicated, but he looks about [[spoiler:ten years old]] most of the time. Towards the end of the game, however, [[spoiler:he unleashes his hidden power, and gains the ability to temporarily transform into a rather adult-looking {{bishonen}} with a bitchin' double-ended lightsaber, unstoppable superpowers, and no pants. Which goes a long way towards justifying the fact that, in the Best Ending, he ends up living with Shania, a RIDICULOUSLY attractive and voluptuous Native American woman. And yes, he still looks like a kid most of the time]]. I guess most people choose not to bug them about it, since their combined power is enough to [[DidYouJustPunchOutCthulhu Punch Out Cthulhu]].
* Will from ''IllusionOfGaia'' can transform into Freedan, an adult swordsman. They look nothing like each other, though.
* Anna, PintsizedPowerhouse of ''ManaKhemiaAlchemistsOfAlrevis'', uses this trick in her FinishingMove.
* From the first ''VideoGame/BloodyRoar'' game, the FinalBoss is Uriko, a cute but creepy little girl who, due to being BrainwashedAndCrazy, turns into a young woman to fight you.
[[/folder]]

[[folder:Western Animation]]
* In ''TransformersTheMovie'', this happens when [[spoiler:Hot Rod opens the Autobot Matrix of Leadership, which has him grow about a foot and half, sounds much older and he becomes a RV truck in his alternate mode]]. Though this ends when [[spoiler:Rodimus Prime gives the Matrix back to a fully restored Optimus Prime and becomes Hot Rod again.]] Of course, in the Japanese continuation [[spoiler:Rodimus Prime gets the Matrix back and regains the larger form when Optimus sacrifices himself ''again'']]
** Another TF example, this time in ''WesternAnimation/TransformersAnimated''. [[spoiler:After discovering that she's a pseudo-Transformer, Sari Sumdac uses her Allspark-enhanced security key on herself to see if she can upgrade herself. She succeeds, converting almost instantly from a girl of approximately 8 years old, to a much taller teenager.]]
* Prince Adam's transformation sequence to He-Man in ''WesternAnimation/HeManAndTheMastersOfTheUniverse2002'' is this. Adam is a slender teenage prince, while He-Man is as badass [[HeroicBuild and big]] as ever.
* Den from ''WesternAnimation/HeavyMetal''.
* Numbuh Two in ''CodenameKidsNextDoor'' uses his technology to turn him into a teenager, and ends up in love with Cree. Unfortunately, the transformation is only temporary, and when Cree finds out, she is disgusted that she was on a date with a kid.
[[/folder]]
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