* In ''Manga/BlackCat'', Mason Ordrosso goes from having a one-page cameo (in the manga), to [[spoiler: becoming the second BigBad in the anime adaptation]].
* When ''Anime/{{Slayers}}'' was novelized, [[RedHeadedHeroine Lina]] and [[IdiotHero Gourry]] were actually the only real protagonists; their companions in the first arc of novels, [[JerkassWoobie Zelgadis]] and [[GenkiGirl Amelia]], were only their allies for that period of time (and even then, Amelia did not appear during the battle with [[BetaBaddie Copy Rezo]] as she did in the anime). They were replaced with [[TheRival Luke]] and [[DeadpanSnarker Milina]] in the second arc of novels. When the anime was becoming popular, however, Zel and Amelia became popular enough to appear in more places than they did, and upon expansion, the "Slayers" became a four-man party instead; just about all of the video games and manga that came followed suit with this. By contrast, Luke and Milina only appeared outside the novels in the ''Hourglass of Falces'' manga, and even there, the group is a [[FiveManBand Six-Man Band]] instead.
* The ''Manga/DragonBall'' series:
** Chi-Chi first appeared as a small warrior princess who can hold her own in a fight, and offered Goku a marriage proposal, which he unwittingly accepts thinking it was a type of food. Years later, an angry Chi-Chi fights Goku in the 23rd World Martial Arts Tournament and they end up together as husband and wife, where from ''Anime/DragonBallZ'' onwards, Chi-Chi goes from ActionGirl to MamaBear, but a few times, she can still kick someone's ass.
** Likewise, Bardock only appeared in one panel in the original manga, only to get his own TV special in the anime, and appear prominently in flashbacks as well.
* Given that the entire series is heavily character-centric, ''Manga/{{Bleach}}'' is a good example; nearly everyone initially appears as supporting characters ([[spoiler:Isshin]] going from comic relief-ridden BumblingDad to the most likely candidate for the series' BigGood) or typical background extras ([[TheSmartGuy Ishida]] first appearing as part of the crowd at Don Kanonji's show and [[DarkActionGirl Harribel's]] introduction as among the twenty [[EliteMooks Arrancar]] that were present when [[NietzscheWannabe Ulquiorra]] gave his report on [[TheHero Ichigo's]] power level to the BigBad), only to gain a much more prominent role several dozen, or even ''hundred'' chapters/episodes later on. Even those that seem as insignificant as the [[FanNickname fodder]][[RedShirt gami]] (less than half of the lieutenants) are likely to, or ''already have'' gotten more screen time and depth over the course of the series. This in mind, it's no wonder the Shinigami [[EnsembleDarkHorse captains and lieutenants]] of the [[BadassArmy Gotei 13]] became the SpotlightStealingSquad. However, the major flaw of this is that, in order to better-develop the Shinigami, practically the ''entire'' FiveManBand has either been shifted OutOfFocus or suffered disconcerting degrees of DemotedToExtra status, and that's ''without'' taking the Karakura High School classmates into consideration.
* In the manga, ''Manga/SailorMoon'''s [[QuirkyMinibossSquad secondary villains]] never lasted beyond one or two chapters. When the [[Anime/SailorMoon original anime]] introduced its MonsterOfTheWeek {{filler}}, they were often given quirkier personalities, some depth to their characters, and increased screen time.
** The fourth season has an especially odd example. The Amazon Trio (three goofy bishounen) stuck around long enough that fans not familiar with the manga might have thought they were the season's primary QuirkyMinibossSquad, even though they would be replaced by the more appropriate Amazoness [[FourIsDeath Quartet]] (who actually got ''less'' appearances.) In the manga, the members of the Trio were one-shot characters who served the Amazoness Quartet and were generally closer to the MonsterOfTheWeek type.
*** As hinted at above, the Amazoness Quartet are an ''inversion'' -- not only are they the main secondary villains of that StoryArc in the manga, but they're some of the very few villains in the manga to be redeemed, and end up becoming the Asteroid Senshi who act as Chibiusa's bodyguards. In the anime, they have less episodes than the Trio did, and never show up again after their redemption, thus never becoming the Asteroid Senshi. Thus, the Quartet were actually DemotedToExtra from manga to anime.
** Jadeite was [[StarterVillain the first villain the girls ever faced]] and was done away with after a few episodes, but latched onto by {{fanfic}} writers because he didn't explicitly die, suffering a FateWorseThanDeath instead. Also, a MonsterOfTheWeek called Thetis is often adopted with him, as she has much more personality to work with than the other monsters (and has a notable crush on Jadeite).
** Another noticeable example is the first season's Nephrite, whose goal was to locate the Silver Crystal. While he was quickly and unceremoniously killed off in the manga, in the anime, Usagi/Serena's friend Naru/Molly kept interfering in his progress, and through continued interaction, [[LoveRedeems he fell for her]], and pulled a last-minute HeelFaceTurn to save her [[RedemptionEqualsDeath at the cost of his own life.]]
** The Sailor Starlights were even noted for being this trope by [[Creator/NaokoTakeuchi the author of the original manga]] (where they're killed off after a few chapters, never to be seen again). Their anime role is basically a mix of Tuxedo Mask and the Outer Senshi, with Seiya's relationship with Usagi given a much bigger focus (due to Seiya being rewritten into a boy who transforms into a girl, rather than a girl crossdressing as a boy.) Oh, and they're the only ones apart from Usagi to survive until the very end.
* In the third season of ''LightNovel/FullMetalPanic'', the assassin twin sisters Yu Fan and Yu Lan had a much expanded role than they had in the novel on which the show was based. In said novel, they were male and died rather quickly. Perhaps their tendency to hold each other [[{{Fanservice}} naked]] had something to do with this change.
* The ''entire'' Montague family in the ''Anime/RomeoXJuliet'' anime. In the [[RomeoAndJuliet original play]], the Capulets had more focus, partially due to Juliet's ArrangedMarriage to Paris; in contrast, Romeo's mother, Lady Montague, has one spoken line and dies from sadness by the end of the play. In the anime, it's reversed: save Juliet, all of the Capulets are dead, Lord Montague is the BigBad, Romeo's the one with an arranged suitor, and [[spoiler:Tybalt is secretly related to Romeo as a cousin, whereas he was Juliet's in the play.]] For individual characters, there's Romeo's relative Benvolio, and Juliet's nurse, who is actually given a name, Cornelia.
* Sumomo in ''Manga/KeroroGunsou'' was, in the manga, a character from a one-shot side story loosely connected to the main comic. In the anime, she was remade into an alien IdolSinger who was taking an impromptu vacation on Earth in her first appearance, and eventually became a recurring character.
** Interestingly, the show seems aware of this, as some characters only appear between long stretches of episodes, prompting the narrator to cheerfully jog the viewer's memory.
* Madame Taki in ''Manga/MermaidMelodyPichiPichiPitch''. In the manga, she's a nondescript fortune teller from Lucia's palace who only appears twice, and one of those times was in a flashback detailing why Lucia was raised as [[RagsToRoyalty a Sleeping Beauty]]. In the anime, she's a ''weird'' fortune teller who came to the surface with Lucia, Nikora and Hippo, and she's also Nikora's "guardian creature", like Hippo to Lucia.
* Miho Nosaka only appeared in one chapter of the ''Manga/YuGiOh'' manga, but was made a main character in the [[Anime/YuGiOhFirstAnimeSeries Toei anime version]] (the lost "first" season). Her personality was drastically altered, too; in the manga, she was a [[ShrinkingViolet gentle, bookish girl]], but in the anime she is sweet, kind, innocent, outgoing, and a {{Kawaiiko}}.
** In the {{Toei}} series, Jounouchi's IllGirl sister Shizuka only appeared in one episode. The [[Anime/YuGiOh second series]] gives her a more extended role and ''two'' [[CrowningMomentOfAwesome Moments Of Awesome]].
** Ryuji Otogi (Duke Devlin in the English version). In the manga, his father sent him to defeat Yugi because [[spoiler:his loss to Yugi's grandfather Sugoroku when they played the Devil's Board Game, which aged him 50 years overnight.]] But, Ryuji isn't that cold-hearted and won't let his dad make him hate Yugi. After that story arc, he was never to be seen again in the manga. As for the anime, he was first shown in a less sympathetic light, wanting revenge on Yugi for defeating Pegasus at Duelist Kingdom. After being beaten at his own game, Dungeon Dice Monsters, he softens up completely and appears throughout the rest of the anime as a supporting character.
*** Huh? Ryuji appears again in the manga as well. He's just a lot more serious than his anime counterpart.
** Remember Tetsu Ushio, that bully who was Dark Yugi's first victim? He's back as a policeman in a supporting role in ''[[Anime/YuGiOh5Ds 5Ds]]'', and even gets to [[HeelFaceTurn act heroic.]]
** Kaiba himself becomes one in the anime version of the Memory World Arc. In the manga after Battle City he's PutOnABus (or in his case, a jet) and only makes a brief cameo in the very last chapter. On the other hand, in the anime he'd already been upgraded from a major supporting character as he was in the manga into the deuteragonist on the show next to Yugi (or tritagonist if you count Yugi and Yami as two characters) and was already greatly involved in just about every filler arc in the series, so the writers probably felt it would be weird if he missed out on the finale. Thus, not only does he wind up dueling Bakura at the beginning of the storyline but eventually he winds up following Yugi and the others into the past as well, ultimately helping [[spoiler: Atem]] take on Zorc and getting a BigDamnHeroes moment by the end.
* Kazuhiko Amagasaki from ''Anime/TenchiMuyo'' only showed up in a brief scene of episode 1, but managed to gain enough popularity to get a bigger role in ''TenchiInTokyo''.
* The [[Anime/FullmetalAlchemist 2003 anime version]] of ''Manga/FullmetalAlchemist'':
** Lust's role in the anime was greatly expanded, and given much more depth than her manga counterpart. In the anime she wants to be human because she feels something is missing, and she is one of the three Homonculi portrayed with great sympathy (Greed and Wrath are the others).
** In the manga, Basque Grand is only mentioned posthumously and seen during the Ishbal flashback arc. He gets more exposure (and a [[AdaptiveVillainy personality change]]) here, and is in fact one of the main recurring antagonists early in the series.
** Shou Tucker, a minor villain who was wasted in fairly short order in the manga, becomes a Chimera in the first anime and returns to cause trouble a few more times.
** Rose became important to the story near the end.
** The Chimeras from Devil's Nest also had greatly expanded roles in the anime, especially Marta. Marta, one of Greed's companions, who had a somewhat significant role in the latter half of the anime, even traveling with the Elrics for a few episodes, unlike the manga where she is killed with the rest of Greed's allies in the Devil's Nest.
** In the manga, Sheska is barely in it after her introduction, with the exception of a few cameos. Sheska got a rather significant amount of screen time and basically became a second heroine next to her best friend Winry.
* Chie Harada was simply one of {{Those Two G|irls}}uys in ''Anime/{{Mai-HiME}}'', and a close friend who provided emotional and moral support to the protagonist, but didn't have much plot importance. Her ''Anime/{{Mai-Otome}}'' counterpart, Chie Hallard, is a high-profile supporting character, even getting pictured on a DVD cover with Aoi, That Other One Girl.
** Not to mention Arika and Nina, the two main characters of ''Mai-Otome'' were practically nonexistent in ''Mai-[=HiME=]''. They had no lines and minimal screen time - Arika only as a cameo in the finale, Nina as simply a LivingProp in Mai's classroom. Only Nina had a name, and it was in Japanese, only revealed in one of the {{Omake}} that briefly lists the names of everyone in Mai's class.
* In one of the ''Manga/{{Naruto}}'' video games, the ANBU organization, specifically members Towa, Komachi and Yugao Uzuki, were given major roles in the storyline. Also, Kakashi wearing an ANBU uniform is playable in the ''Naruto: Ultimate Ninja'' games.
** As if Iruka wasn't already enough of an EnsembleDarkHorse, [[NarutoTheAbridgedSeries the Abridged Series]] gets him into a rivalry with ''Kakashi''.
** A filler episode of the anime turns Mizuki (a ''very'' minor villain who appeared in the first episode of the series) into that arc's BigBad (and in fact [[ArcWelding had him working for the regular Big Bad]]).
** Matsuri, formerly a nameless FanGirl of Gaara's in Part II, appears in the last of the Part 1 filler arcs as the first student to accept him as her teacher, and who gets kidnapped by the villains of the arc to lure him out. She also gets some lines of dialogue in the anime version of the Gaara arc.
*** And proceeded to get her very own entry into the official databook under that name.
** Chiriku, one of Asuma's old friends and one of the 12 Guardian Ninjas, gets more of a role in the Temple of Fire arc.
* Kaworu from ''Anime/NeonGenesisEvangelion'' gets this treatment in the ''RebuildOfEvangelion'' films, where he has a greater presence throughout the actual storyline. It sometimes takes fans a bit of time to realize that outside of the movies, he only appeared in one episode, and had the approximate screentime of Jet Alone (remember JA? We didn't think so.) That said, he ''was'' important to the plot, but most of the character attributes were retconned since they couldn't actually be displayed in what little screentime he had.
** In the franchise, Mana Kirishima counts as well, being one of the very few [[CanonImmigrant non-canon characters to appear in more than one spin-off]] (debuts in ''Girlfriend of Steel'', then manages to get into ''Shinji Ikari Raising Project'').
** Not only do we [[HeWhoMustNotBeSeen never actually see or hear]] Toji's sister, but we [[NoNameGiven don't even get to know her name]] either! Cut to the third ''Rebuild'' movie, [[spoiler: where she now acts as a supporting character after the TimeSkip and is given the official name of Sakura Suzuhara]].
* Shin, Kenshiro's first notable adversary in ''FistOfTheNorthStar'', was killed off rather quickly in the original manga after playing out his role to serve [[TokenMotivationalNemesis as exposition on Kenshiro's background and motivation]], since the future of the serial was still uncertain at the time. In the TV series, Shin's story arc was [[AdaptationExpansion extended]] beyond the events of the original manga, with Shin getting much greater development. One episode gives his own [[CrowningMomentOfAwesome moment of glory]] when he singlehandedly thwarts a rebellion within his own subordinates, displaying a bit of his martial art skills before confronting Kenshiro.
* Franz in ''Anime/{{Gankutsuou}}''. In ''Literature/TheCountOfMonteCristo'' he's a minor character who [[TheWatson receives exposition]] in one short section of the story and serves as an easily overcome roadblock to the OfficialCouple. In the anime he becomes integral to the two main characters' relationship.
* ''Anime/CodeGeass'''s Nina Einstein is arguably a rather uncommon case on how this isn't always a good thing. At first she seemed to be nothing more than a quiet, shy little {{Meganekko}} whom is just one of Milly's friends. However, due to her knowledge in science (among other things), her role gradually gets considerably larger. But the bad news is that this is when her reputation of being "an evil insane racist" was starting to grow as well. (Granted, the show tries to redeem her later on in R2, [[BrokenBase but lets just say not everyone was willing to forgive her.]]) Though in a way people probably would've liked her more right from the start if she was just one of Milly's little friends and pretty much stayed that way (in fact, the manga adaptation actually does just this.)
** In a way Lelouch and Nunally's mother Marianne is like this as well; in the beginning she seemed to be a token "Kind Mother whose only purpose is to have died in a flashback just so main characters can have a sad backstory". However later on in R2 let's just say that wasn't [[BackFromTheDead quite the case]], and it appears that she is just as bad as her dear hubby Charles. Granted it was all a part of their rather convoluted plan for peace [[Anime/NeonGenesisEvangelion that reminded people about a certain other plan lets just say.]] Not to mention on how the only reason why Lelouch and Nunally were living their lives like they were before the whole story started is that it was all a part of Charles and Marianne's plan. So in short as for later on R2 Marianne went from one of the better mothers in the show to quite possibly the worst mother ever.
** While some characters were DemotedToExtra's for "Lelouch of The Rebellion" (manga), some such as Euphemia were given far bigger parts.
** Jeremiah Gottwald also got an expanded role in R2 after some ExecutiveMeddling. Apparently, Jeremiah gained such a fanbase in the first season, that the producer rewrote the script to include him in R2 instead keeping him killed off. [[LargeHam It]] [[MemeticMutation was]] [[CrowningMomentOfAwesome awesome.]]
* In ''Manga/OnePiece'', Michael and Hoichael, two delinquents in Water 7, are once suspected as being responsible for the assassination attempt on Water 7, and later try to mug Zoro, only to get beaten up and forced to lead him back to the rest of the crew. In the Post-Enies Lobby arc, they appear in a filler episode as part of a makeshift family consisting of a woman and her "children," who are not blood-related, and Zoro helps defeat the collectors after they hire Mikazaki of the Crescent Moon (another AscendedExtra, a pirate with a 38 million bounty who got [[TheWorfEffect Worfed]] by the Galley-La company).
** Silvers Rayleigh first appeared in a single panel at the beginning of the series. Fast forward almost '''500''' chapters later, and not only is he revealed to be [[spoiler: Gol D. Roger's first mate]], but he also [[spoiler: helps train Luffy during the timeskip.]]
** A more recent example is Trafalgar Law, who appeared during the Sabaody Archipelago Arc as a minor character. He later shows up at the end of the Marineford War to aid an out-of-commission Luffy, then after a few arcs, reappears again as a major ally in the Punk Hazard Arc and Dressrosa Arc. Granted, it was hinted that the Eleven Supernovas would have bigger roles to play in future story events.
* ''Anime/DigimonTamers'' had a few of these. BridgeBunny Riley/Reika became an AscendedExtra later on in the series, although that might have been because she was dating the not-bad-guy of the series (Yamaki). Takato's friends Jeri, Kazu, and Kenta; as well as Henry's little sister Suzie, also become this trope when all four of them become {{Sixth Ranger}}s.
* Sae's sister Chika is arguably important in the ''HidamariSketch'' anime, but you won't be able to find her in the manga -- she is only referenced to and not given a name there.
* Renko Kamishakujii and Koyuki Asagiri, while they both had minor roles in the first ''KujibikiUnbalance'' "series" (it's tough to tell with only three episodes), they were major characters in the TV series version. In contrast, Komaki and Izumi, once major characters, were reduced to side roles.
* ''Manga/OuranHighSchoolHostClub'''s Renge Houshakuji was introduced early on with her own chapter, and then she faded to the background. She does still make occasional cameo appearances, though. Bisco Hatori-sensei had mentioned Renge was intended to be a recurring character, but for whatever reason it never happened. Her role in the anime is expanded quite a bit as an AsYouKnow, GenreSavvy FanGirl, and she does a few of the tasks Tamaki had initially done in the manga (such as helping Nekozawa with his photophobia). Bisco-sensei was happy to see Renge given more screentime in the anime, even if her appearances became less frequent toward the finale.
* "Lum's Stormtroopers" in ''Manga/UruseiYatsura''. In the manga, they were minor characters who [[NoNameGiven didn't even have nicknames given]], weren't really distinguished from each other (to the point that it's not consistent about whether there are four of five of them), and [[ChuckCunninghamSyndrome stop appearing]] fairly early on in the series. In the anime, they're given the nicknames "Megane", "Chibi", "Kakugari", and "Perm", Megane is a supporting character about as important as (for example) Mendo or Ten, and Perm is sort of a [[CompositeCharacter composite]] of two characters from the manga: minor character Kosuke Shirai, and the nameless permed-hair guy. (Kosuke Shirai himself eventually appeared in the anime in the 2008 OVA.)
* Konori Mii from ''Manga/ACertainScientificRailgun'' was originally a nameless Judgement character in the manga, but in the anime, she got backstory, character development, her own fair share of moments and voicing from Creator/KanaUeda.
** Uiharu is a very small character in ''Index'' but a main cast member in ''Railgun''.
* Simply because of the nature of the series, this arguably happens a lot in ''Manga/AxisPowersHetalia''. Examples may include the Nordics, Micronations or characters that only have a basic design.
** This is also arguably how the Allies and the more prominent Nations like Poland, Lithuania and the [[FanNickname Frying Pangle]] (Austria, Hungary, Prussia) started off in the first place.
* ''BrigadoonMarinAndMelan'' was an AnimeFirst series. When the manga came out, Aloma was given a much greater role, including the role of alternative love interest for Marin.
* [[AlphaBitch Nanami]] from ''Anime/RevolutionaryGirlUtena''. She only appears in a photo in the manga, but becomes a regular secondary character and a duelist in the anime.
* In the ''Manga/ExcelSaga'' manga, Pedro appears only a few panels before dying. He still dies as quickly in [[Anime/ExcelSaga the anime]], but his story continues, with continuity that the rest of the series lacks.
* The author of ''DGrayMan'' revealed in her commentary that [[CuteClumsyGirl Miranda Lotto]] was originally supposed to be an arc character never to be seen again, but as she got into the story she took a liking to her, made her an exorcist and had her [[SixthRanger join the main cast]] a couple of arcs later.
* General Gunther Reindardt of ''Anime/{{Robotech}}'': Originally, the animation for the final series made many fans assume that the returning Expeditionary fleet was destroyed by the Invids' transcendence to a higher plane. The Jack [=McKinney=] novels assumed this. It was probably true in the original Japanese version of Mospeada. At that time, the General didn't yet have a name and his connection to Admiral Hunter was JustFollowingOrders. He was named in the novels and was established as one of Rick Hunter's close friends. After 20 years of debating what was seen in the animation, the 2007 movie WesternAnimation/RobotechTheShadowChronicles not only made Reinhardt one of the lead characters, but showed that the Invids' transcendence destroyed only the Neutron-S missiles, and not any manned Expeditionary ships, ensuring that Reinhardt and his crew survive to be in sequels.
* Misty and Brock of ''Anime/{{Pokemon}}'' would qualify as this as in the [[VideoGame/PokemonRedAndBlue games the show was based on]] they merely appeared as [[BossBattle the first two Gym Leaders]].
** In ''Best Wishes'', they repeat this with Cilan and Iris.
** Pikachu was nothing in ''VideoGame/PokemonRedAndBlue''. As explained [[http://chromagic.blogspot.com/2011/01/my-opinions-on-every-pokemon-ever_24.html here]], it was turned from an insignificant unevolved Pokémon into the poster boy for the entire thing.
** ''Manga/PokemonSpecial'' has this with nearly every Gym Leader, and quite a few other people. A noticeable example is Courtney, a Team Magma admin. She never appeared in the anime, never appeared in any other manga, doesn't have any official art, was fought once, and never appeared in the timeline canon ''Emerald''. But she's the most developed of the admins for either team, maybe even more-so then the leaders.
*** For an "in house" example there's Professor Yanase who initially was just a scientist on the [[spoiler:control Rayquaza]] project and later is revealed to be Yanase Berlitz, Platinum's mother.
** Pokemon adaptations in general tend to do this. Any important NPC will probably have some plot significance for at least a chapter.
* ''MahouSenseiNegima'' exemplifies this trope. Several characters who barely got any panels per volume to their selves for the first few volumes get entire sub-plots revolving around them. A few examples:
** Natsumi, Kazumi, Ku Fei and Mana are barely mentioned in the beginning yet became pivotal players in the most recent story arc.
** The [[spoiler:defeat Rakan]] revolved partly around [[spoiler:Ako trying to work out her feelings for Negi/Nagi]].
** Chao Lingshen had an entire story ''arc'' written around her. If that's not ascension of an extra, I don't know what is.
* Yuka Hanazawa of ''Manga/{{Beelzebub}}'' was originally just one of [[ThoseTwoGuys two occasional characters]] in The Red Tails, usually just appearing for a quick background appearance. As of late, she's taken on a more prominent role, frequently seen hanging around Kanzaki.
* In the original {{OVA}} for ''Anime/BlackRockShooter'', Yuu was little more than a side character ([[OnlyOneName she didn't even have a last name]]), while Black★Gold Saw and Strength [[TheCameo appeared without much relevance to the plot]]. The 2012 anime increased the roles of all three characters [[spoiler: particularly Yuu and Strength.]]
* Shiro Sanada in SpaceBattleshipYamato: Originally, he was just the ships SmartGuy. And due to the fact that he was a little older than the mostly young crew, it was expected that he would die as is common for mature characters in an ensemble cast of mostly youngsters (so that the young characters can grow and develop). Sanada shares with Kodai the distinction of being the Yamato Sagas two most longeval characters. He reunites with Kodai in the 2010 Yamato Ressurection [[spoiler: in which Sanada now outranks captian Kodai]].
* Poor, poor [[PandoraHearts Elliot and Leo]] get this in the worst possible way with the former [[spoiler:finally seeing the TomatoInTheMirror and realizing that he is the one who has been offing his family members all along, a revelation that leads to his HeroicSacrifice,]] and the latter [[spoiler:[[ItsAllMyFault blaming himself]] for his best friend's death and eventually pulling a FaceHeelTurn because he can't handle the guilt, joining the Baskervilles and reawakening Glen Baskerville's soul inside him, thus becoming an antagonist to Oz, who had grown to see him as a friend]].
* Despite being one of the lesser-known characters of the franchise, Armor was a main character in ''MarvelAnime: Comicbook/{{X-Men}}''. This lead to her getting some more spotlight in the comics, such as her major role in the ''Alpha and Omega'' mini-series.
* Yuki Ushimaru from ''Manga/GakuenBabysitters'' slowly rises from her status as a walking RunningGag when she gets a rival for Ryuuichi's affections, resulting in slightly more frequent and significant appearances afterwards.
* Sentaro Daimonji in ''RanmaOneHalf'' was a minor character who appeared in a brief three-chapter-storyline early on in the manga. In the anime, he was made into a recurring character that generally popped up OnceASeason.
* Nanoha Takamachi was formerly a very minor character from ''TriangleHeart3''. Eventually it was decided to create a MagicalGirl SpinOff series starring Nanoha. Adding a few HumongousMecha-related tropes turned [[MagicalGirlLyricalNanoha Nanoha and her show]] into a very [[LyricalNanoha successful franchise]] [[MorePopularSpinoff that has drastically eclipsed the original in popularity.]]
** Nanoha's daughter Vivio gets her own SpinOff as well.
** Nanoha's [[ThoseTwoGuys two friends Suzuka and Alisa]], and Fate's "older sister" [[PosthumousCharacter Alicia]] become main characters and {{Magical Girl}}s in ''Manga/MagicalGirlLyricalNanohaINNOCENT'', together with Nanoha and Fate. It's a AlternativeContinuity, and the Magical Girls are actually Cyber Magical Girls.
* In ''Anime/PuellaMagiMadokaMagica'', the witch Charlotte was just [[MonsterOfTheWeek the enemy of one episode]]...albeit one that had a [[KnightOfCerebus major impact on the plot.]] In ''Anime/PuellaMagiMadokaMagicaTheMovieRebellion'' Charlotte [[BreakoutCharacter reappears in an expanded role.]]
* In ''GaikingLegendOfDaikuMaryu'', Kain starts out as one of Nouza's subordinates, and is the only one to survive. [[spoiler: During the final battle, he even pilots Vulking as a decoy to allow Nouza to sneak into the enemy base]]. In addition, Daiya's friend Naoto had only featured in the first episode, but makes a reappearance later on, [[piloting the Daiku Maryu after its regular helmsman is seriously injured]].
* AscendedExtra: Ignacio Axis in the animated adaptation of ''LightNovel/ToaruHikuushiENoKoiuta''. The anime seems to be treating him as one of ''four'' protagonists, if promotional material is anything to go by. In the novels, however, Ignacio is considered a supporting character only, with the original story focusing on Kal-el, Claire and Ariel.
* In the manga adaptation for ''Manga/KingdomHeartsII'', Sark was given more scenes and played a major role during the second half of the "Space Paranoids arc", including taking Tron captive and torturing him, and later ambushing the party when the [=DTD=] is accessed. Following his defeat, [[spoiler: we learn that he once believed in the users like Tron does, but lost faith when it appeared that Ansem betrayed them, and warns Tron to let go of his faith while he still can, which causes Sora to feel sorry for Sark]].

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