Took a Level In Kindness

""And what happened then? Well, in Whoville they say, that the Grinch's small heart grew three sizes that day.""

- How the Grinch Stole Christmas

A Jerkass softens over time, and becomes either a Jerk with a Heart of Gold or not a jerk at all. Usually this can be due to Character Development. Badass Decay and Heel Face Turn may be involved as well. In some cases this may be a case of Characterisation Marches On; as the series progresses, the writers realised that a nicer character fit the changing tone better than the original idea.

If done over the course of one episode or short-story, this may have been to set up an Aesop.

Naturally, the Counter Trope of Took a Level in Jerkass. Compare to Defrosting Ice Queen, which focuses on a specific Love Interest bringing a character out of their shell.

Anime and Manga

 * Sakura Haruno from Naruto. She goes from a Jerkass Tsundere who beats up Naruto and swoons over Sasuke, to a more vulnerable but quite more kind-hearted Combat Medic. To be fair, she showed signs of Character Development even before she got her iconic Important Haircut: a scene in the Haku and Zabuza arc has her giving candy to a Street Urchin and then cries Tender Tears when she learns how Tazuna's home is due to Gato and his group.
 * After his defeat by Naruto, Neji goes from an Jerkass Arrogant Kung Fu Guy who harshly beat his cousin Hinata to a generally nice guy who shows concern when she is injured and supports her crush on Naruto.
 * Kankuro also qualifies, starting off as an arrogant, Hot-Blooded Jerkass and becoming noticeably kinder in Shippuuden, partly due to his improving relationship with Gaara.
 * Piccolo from Dragonball Z went from a raving, sadistic psychopath and a literal Demon prince, to one of the most levelheaded characters, all thanks to the kindness of a single child!
 * Granted, this is probably because he only turned after he fulfilled his revenge against Goku.
 * Ken from Digimon Adventure 02 after his Heel Face Turn. Particularly appropriate in that Kindness was always intended to be his Crest from the beginning.
 * Also Rika from Digimon Tamers gradually becomes less cold-hearted and friendlier towards Takato, Henry, and the other games.
 * Syaoran Li of Cardcaptor Sakura evolves from an Arrogant Kung Fu Guy with Tsundere qualities to meek and soft natured Dogged Nice Guy for Sakura. Meiling of the anime adaption goes through a similar evolution. Both cases are largely due to Sakura's own increasingly empathic and innocent aspects (though granted, she was already rather sweet natured by the start of the series' run).
 * In Haibane Renmei, this is an important part of character development.
 * Kyouko from Puella Magi Madoka Magica starts as an Ax Crazy Jerkass. But after learning, she starts showing her Hidden Heart of Gold, more specifically towards.
 * Guts of Berserk, upon finding Casca again and gaining new True Companions, has begun abandoning his cold, ruthless and vengeful Black Swordsman persona in favor of something resembling his original nature for the first time since the Eclipse. Mind you, he still has a rather nasty Enemy Within to deal with due to the vendetta that he was on for two years.
 * Even better would be Farnese, who was once a cold, Knight Templar, Pyromaniac who wanted nothing more than to burn people at the stake for her own satisfaction and to see Guts dead. But after the events at the Tower of Conviction, and wanting to atone for her past actions by following Guts, she has grown considerably kinder and is even shown to being sort of naive and manipulable.
 * Gary Oak/Shigeru in Pokémon becomes much nicer to Ash around the Johto arc after his Break the Haughty phase in the Kanto arc. By the end of the Johto arc, he and Ash finally become friends again after so many years to being rivals (which sticks when they meet again in Sinnoh).
 * This is the driving force behind the plot of Onani Master Kurosawa: A cynical jerk who sequesters himself from the rest of the world softens over time, beginning with  and ultimately culminating in
 * Nami from One Piece. Gradually as the series has gone on, but especially after the timeskip. From forgiving Hachi, to immediately hugging Usopp and Chopper when they reunite, to even immediately forgiving Jinbei for letting Arlong loose on East Blue, she's come a pretty long way from the Jerkass Facade she started out with.
 * Not to mention, she almost never hits her crewmates anymore, starting after the timeskip. Though this maybe because of her crewmates beating her to the punch.
 * Inuyasha: Inuyasha, Sesshoumaru, Kouga, and Kagura all experience this at varying speeds and to varying degrees.

Fan Works

 * Calvin and Hobbes: The Series' iteration of Calvin is much more likely to do the right thing than his comic counterpart.
 * In The Best Night Ever, a core focus of the story is Prince Blueblood taking several levels in kindness.

Films -- Live-Action

 * The film Son Of Godzilla is the start of showing the King Of The Monster's more loving fatherly side. Especially towards the end where he
 * In Bad Santa, the main character starts being a complete Jerkass, but eventually becames a Jerk with a Heart of Gold.

Literature

 * The Grinch, from How the Grinch Stole Christmas, provides the page quote.
 * Ebeneezer Scrooge from A Christmas Carol.
 * Prince Garrid from Tales of the Frog Princess, a Ladykiller in Love, became a genuinely better person so he could be with Li'l.
 * Eustace in The Voyage of the Dawn Treader.
 * Happens a lot in the Chalet School series. Girls who start off as bitchy, sulky or standoffish will often come to learn the error of their ways and become nicer people after being introduced to the ways of the school, or getting a good ticking-off from one of the mistresses. And if that doesn't work, there's always a handy accident; for instance, Eustacia Benson injures her back after running away from the school, is confined to a wheelchair for some time and becomes a much nicer person.
 * Peter Pan in Scarlet takes it for granted that Slightly, formerly a condescending, cowardly little snob, grew up to be kind, sensitive and "as gentle as a lamb". Of course, the original novel and the various drafts of the play implied that Slightly had his ego brought down to size after the boys left Neverland, and in Peter Pan in Scarlet, so suffering probably sweetened him a little.
 * James Potter started out as The Bully and then eventually becameHead Boy in his seventh year.
 * Matteo in Someone Elses War, who goes from a snobby, condescending brat to a loving young man who will risk his life and compromise his ideals if it means saving his friends.

Live-Action TV

 * Cordelia on Angel went through this.
 * So did Faith. She becomes even kinder and more morally centered than before her Face Heel Turn, to the point where some fans claim Faith is better, gooder than the rest of the cast.
 * Luke on the O.C
 * Star Trek: The Klingons went from bad guys to Good Is Not Nice between TOS and TNG. The final TOS movie shows us how. However, it's disputable how much they've changed really when it comes to conquering: they're chummier with the Federation, but they may well be no different to other races.
 * From TOS, Elaan from Elaan of Troyius.
 * Albert Rosenfeld, Twin Peaks
 * Waldo Geraldo Faldo, Family Matters
 * Andy Dwyer, Parks and Recreation
 * Andy Bernard, The Office
 * Over five seasons, both Blair Waldorf and Chuck Bass on Gossip Girl have gradually become kinder and more accepting. Both are still quite sarcastic and snarky, but they're no longer deliberately malicious or cruel.
 * The Doctor, from Doctor Who. Yeah, you might know him now as a goofy fun-loving guy who likes to save innocents, but his first incarnation wasn't nearly as nice. His very first story featured him kidnapping two humans because he didn't want them exposing his secret, and he often showed no qualms about killing people they encountered. Part of the change was definitely deliberate, as the writers wrote him becoming softer and kinder over his run, but part of the change is due to the change of the show's premise. When the Doctor started out he was a mysterious presence to intrigue the viewers and the show's real protagonists, the companions Ian and Barbara, whereas now much of the Doctor's back-story is known, and he often functions as the main hero.
 * Note that the Jerkass persona can be chalked up to Early Installment Weirdness: the Doctor is only downright malicious in his first three stories and softens up afterwards, and his negative traits almost entirely disappear by the end of his first series. William Hartnell spends most of Season 2 playing an eccentric loveable grandfather figure who is constantly giggling and calling people "my dear boy".
 * As evidenced in "The Waters of Mars," nasty things happen when the Doctor doesn't have a companion. Maybe the Doctor needed Ian and Barbara's influence to take a level.
 * Ziva David from NCIS has in the past couple of seasons evolved softer qualities including a big sister instinct for McGee. Though it may be those aspects of her personality were always there and she needed to feel at home on the team.

Video Games

 * Riku from Kingdom Hearts goes from Arrogant Kung Fu Guy to Rival Turned Evil in the first game, but at the end snaps out of it and spends Kingdom Hearts II as The Atoner.
 * Duncan from Dragon Age Origins: In a universe as dark and depressing as Dragon Age can be, right from the start of the game Duncan is a beacon of hope before the player becomes one.
 * If he survived the first game, Zevran has been spending most of the time frame that Dragon Age II encompasses only killing the Crows that try to track him down. Okay, nothing too new, and Zevran was always much more laid-back than one would expect from an ex-assassin, but Considering this is the man who casually admitted he enjoyed killing (to an extent) and has killed innocents, or gotten them killed through his actions more than once, in the first game, this is quite the Character Development.
 * Somewhere between Ratchet & Clank and Going Commando Ratchet evolved from being a Jerk with a Heart of Gold (and something of The Scrappy) to a generally nice (if not rather snarky) protagonist. Some fans accredit this to James Arnold Taylor becoming his voice actor.
 * No, that was near the end of the first game where he realized he was being a jerk after finding out that
 * The rival Silver from Pokémon could count as this. He goes from a cruel, harsh person, but eventually becomes friendlier towards the player and his own Pokemon- to the point where his Golbat evolves into a Crobat after reaching high happiness.
 * Midna from The Legend of Zelda: Twilight Princess starts off as very selfish, pushy, and only out to save her own world, without really caring about Hyrule. After seeing the kindness and bravery of Hyrule's people -especially Princess Zelda- she evolves into more of a Jerk with a Heart of Gold.
 * Also from the Zelda series is Groose from Skyward Sword. He starts off as a typical arrogant and pompous Jerk Jock who has it in for Link, but at one point he follows Link to the land below the clouds and witnesses Link fighting and resealing the game's Sealed Evil in a Can. Though he's at first disillusioned over his own apparent uselessness, he comes to respect Link and begins to grow considerably more noble, even becoming a crucial ally to Link in a number of boss battles.
 * In the first two games of the Mass Effect series, Turian Councilor Sparatus is an ass to Shepard and to humans in general. Come the third game, when it's been made clear that Shepard was utterly correct all along, he is the first one of the trio to provide Shepard aid in the form of vital intel, and is the only one of the three who doesn't start off as cold and dismissive toward Shep. Also, the third game has now-Councilor Udina, after being such a dismissive jerk in the previous game, being surprisingly supportive and polite toward Shepard....
 * Miles Edgeworth from the Ace Attorney series goes from being the ruthless Demon Prosecutor, concerned only with maintaining his perfect prosecution record even through shady means, to pursuing the truth for truth's sake and being a genuine friend and ally to Phoenix, Maya, and others (most notably, ). By the time we see him in his most recent appearance, he's willing to risk loss of career and arrest in order to help Kay Faraday.

Web Comics
"EB: all im saying is don't you think monster howie mandel has the power to do something as simple as reseal a bottle? EB: try using your brain numbnuts."
 * Karkat in Homestuck becomes less of a Troll and more interested in the success of his prior antagonists. And if he's not a Jerk with a Heart of Gold, at least he's a shrewd enough leader to know when to play Team Mom for the other trolls.
 * John, too. As he becomes more of a Messiah—especially when contrasted with the other kids' Character Development, which often took them in darker directions—it can be hard to remember that this is the same guy that who, in his first pesterlog, responded to Dave's gleeful discovery of a bottle of apple juice by joking that it might actually be full of pee.

Western Animation

 * Stan Smith from American Dad. He still has his Jerkass moments, but the show's Character Development did him a lot of good.
 * The large majority of the Smith family have gone in a similar direction to a lesser extent (par Roger who swerved several times in the opposite direction, likely to balance the more sympathetic characters by acting as a Token Evil Teammate.
 * The episode ''Frannie 911' revolves around this trope, in which Roger tries to be nicer so he can win back the family's love. However, it turns out that being nice is lethal for Roger's kind, and has to be a jerk if we wants to live.
 * Even Roger seems to be getting slightly tamer. While he still has a few highly malicious moments, he does on occasion show genuine sympathy to the other Smiths (particularly Stan) and even shows capability of learning a Aesop (something he was previously completely incapable of doing). At the very least he doesn't seem quite as outspokenly callous as he was in the third and fourth season.
 * Stewie Griffin from Family Guy, combined with some Badass Decay. Still, it's interesting to watch how the original "evil" character become much kinder while his family Took a Level in Jerkass.
 * Meg similarly is far less bratty and self centered in recent seasons, if perhaps only because she's so desperate for affection.
 * Homer Simpson. During season 1 he used to be angry all the time, but he became sweeter after season 2. Then, when the show's Flanderization kicked in, he Took a Level in Jerkass.
 * Arguably this evolution had begun since the show's beginning. Even Season One Homer is a far more sentimental and devoted father in comparison to his counterpart in The Tracey Ullman Show shorts.
 * And then there's "Alone Again, Natrua-Diddily", where Homer promises to treat Ned Flanders less like a Sitcom Arch Nemesis, complete with a Single Tear.
 * The one episode where he becomes friends with Flanders, he's back to hating him by the end.
 * Prince Zuko from Avatar: The Last Airbender, during season 3.
 * Agent Six in Generator Rex, in the episode "String Theory" where the seemingly mindlessly loyal agent actually defused the nuclear bomb rather than allow millions of innocents to die.
 * Cemented later in "Promises promises" when we see how much he had to do with Rex being accepted by the group.
 * Due to Heel Face Turns, Kevin Levin in the Ben 10 metaseries, and later
 * While more a difference in interpretation than a canonical evolution in personality, Eeyore in Disney's Winnie the Pooh Animated Adaptations was given a much gentler persona in comparison to his original novel counterpart. This evolved to the point that Eeyore is distinguished as one of the most recognisable Woobies in Western Animation.
 * Buford from Phineas and Ferb, who was a bully in his first appearance, a Punch Clock Villain in his second, and afterward only makes token attempts to pretend he doesn't like everybody else.
 * Film historian Leonard Maltin notes that when Mickey Mouse first arrived on the screens, he was hardly a model of good behaviour. Mickey soon evolved into The Everyman, with the Jerkass torch being passed to Donald Duck.
 * June from KaBlam! became this in season four. She still had some cynical moments, but she became a lot nicer.
 * Heather from Total Drama Island used to be a mean Jerkass, but due to all the hell that people put her through, she suddenly changes to be nicer, starting with the unlucky Cody.
 * In Regular Show, Muscle Man has undergone this. Formerly a Jerkass, he's become a Jerk with a Heart of Gold who views Mordecai and Rigby as friends.
 * You know who else views Mordecai and Rigby as friends?
 * Yosemite Sam goes from mean in the original shorts to nice in The Looney Tunes Show.
 * In the My Little Pony Friendship Is Magic episode Hurricane Fluttershy—three episodes after we see Angel Bunny at his nastiest—he's comforting a distraught Fluttershy and helping her improve her flying.
 * Two possible sources of this: The aforementioned episode featuring an especially nasty Angel was also the one in which Fluttershy Additionally, it has been hinted at before that Angel, despite his jerky nature, genuinely cares for Fluttershy, almost as if he feels that he is the only one who should be allowed to be cruel to her.