A stiff character learns and grows from unwanted interaction with annoying and eccentric people.
The focus character is a fairly stiff guy (rarely a gal), may be the Only Sane Man, The Comically Serious or a Jerkass of the "stick up his rear" type, and often comes across as an Ineffectual Loner. He may not be content with his life, but it's stable, and he probably has a long-term plan for fixing what he thinks is wrong, if he can just get the right breaks. Instead, he is dragged into wacky hijinks by the other characters against his will, making a mess of his life. But implicitly or explicitly, the goal in the story is to make him a better person by putting him through "horrible" experiences - or at least ones he considers horrible, in order to show him the brighter side of things.
May involve a Manic Pixie Dream Girl, but in most examples, it's an entire cast imposing on the stiff guy's time, money and patience. The Power of Friendship is usually evoked by the end of the story. There may be a montage as the character remembers how things used to be, and how despite how much the other characters irritate them, they have made stiff guy a better person by getting him to take off his Jade-Colored Glasses.
Contrast Defrosting Ice Queen, an Always Female version, and Unsympathetic Comedy Protagonist, who may have a similar personality and equally annoying cohorts, but does not have the Character Development.
- Rozen Maiden: Jun is a hikikomori until Shinku forces him to be her "medium", interacting with her and the other crazy dolls and eventually humans brings him out of his shell.
- Zatch Bell!: Kiyomaro Takamine is initially an antisocial Teen Genius who doesn't get along with his classmates, but when his Mamodo partner Zatch comes into his life, he starts attending school again, and makes friends with a whole crew of weirdos, both in class and from around the world. Interacting with so many strange people and finally making friends helps Kiyomaro open up and become a kinder, more compassionate person, who can put others before himself and use his intelligence altruistically.
- Midori Days: Seiji thinks that his problem is not being able to get a girlfriend, but that's actually just a symptom of his general inability to interact non-violently with others. Having to protect Midori and her secret, and deal with wacky people he can't just punch, brings out his better qualities.
- Explicit in the anime version of Haunted Junction: Haruto says I Just Want to Be Normal, but is constantly dragged into supernatural mayhem. In the final episode it's shown that the school spirits have been tormenting him specifically to avert a Bad Future in which not only are they gone he lives a "normal life" but never emotionally connects with anyone including his future wife and child. Which seems to lead into a happy ending...except that said Preacher's Kid was made so miserable by the constant torment that he voluntarily participated in a plan to kill or imprison all the school spirits; and there's no indication that things are going to get better for him.
- The manga plays it straighter. Haruto is still not completely happy in the council, but is more resilient and his relationship with the ghosts is smoother.
- The plot of Happy Lesson kicks off when Chitose's teachers decide that what he really needs are five mothers running his life. (He discovers, much to everyone's surprise, that he does become a more well-adjusted person because of them.)
- Sumomomo Momomo: Koushi never wanted an Arranged Marriage or to be surrounded by lunatic martial artists bent on killing/loving him. But after Momoko finally admits she knows he doesn't love her, Koushi acknowledges that his experiences have broken him out of his fear of confronting other people (even if he's still a physical coward.)
- The residents of Maison Ikkoku spend most of their time driving Yusaku Godai insane with their alcohol-induced insanity, but also end up somehow making him the man he needs to be for Kyoko, as well as get Kyoko to reflect on her feelings for him.
- The Haruhi Suzumiya works imply this is the case for Kyon, who became a much more outgoing and likable guy after exposure to the SOS Brigade. They invert it with Haruhi, who became a more sympathetic person by hanging out with apparently normal people.
- Arakawa Under the Bridge: Ko/Recruit starts the series as someone who sees all human interaction as a series of debt transactions, in which he must never remain the debtor. Being forced to live with the zany riverbank community allows him to learn to interact with other people on the basis of honest emotion, without being concerned about who "owes" who. Lampshaded when Recruit realizes he hasn't had an asthma attack (symptomatic of his fear of debt) in quite some time.
- Baccano!'s Firo Prochainezo outright admits this to himself in Alice in Jails. Early Firo was cynical and occasionally downright vicious (as demonstrated by his "excessive self defense" against a mugger in his Establishing Character Moment). Then Isaac and Miria came along...
- Isaac and Miria themselves are a traveling example of the loony friends: throughout the series they inspire Ennis to escape her abusive master, encourage Jacuzzi to fight against murderous cultists, and help Czeslaw overcome his guilt of Killing in Self-Defense. The novels imply that the couple also saved each other from unpleasant family environments.
- Justified example: Haruka Kotoura of Kotoura-san has been pretending to be a jerk to keep herself from being emotionally hurt by being forever alone, but Manabe and the ESP club can see right through it and know how much she's actually hurting herself with it. If not for them, she would have been a Broken Bird for who knows how much longer or worse as Detective Tsukino shows us in episodes 9 through 11 as a jealous, child-beating criminal.
- Kagerou Daze: Ene's teasing and pranking of Shintaro is an attempt to invoke this trope and help Shintaro get over his apathy towards the world. Shintaro's involvement with the quirky members of the Mekakushi-dan does lead to him becoming a more caring, sociable person while also driving him up the wall.
- In The Truth About Forever by Sarah Dessen, the Wish Catering crew for Macy. Even her sister Caroline notices the change, and she only visits sporadically.
- Arthur Dent's utterly miserable struggles through a World Gone Mad in The Hitchhiker's Guide to the Galaxy do improve his bravery and will to the point where he's able to prevent Trillian leaving a party with obvious jerk Thor (a reversal of when he failed to prevent Trillian leaving a party with obvious jerk Zaphod in the backstory), fend off his accidental nemesis, and learn to fly. At a couple of points, he even tires of the simple life he repeatedly claims to long for and decides to go off travelling through space again. On the other hand, it does leave him a scared, frustrated and rather depressed wreck.
- A Mage's Power: Zigzagged Trope. Aio, Eric's first friend in Tariatla, is certainly loony. His schoolfriends, Revas, Oito and Annala, are not loony in the least, but his guild friends are plenty loony. All of them work together to help him grow a spine.
- In Harry Potter, Word of God confirms that part of Luna's purpose was to demonstrate Harry's Character Development as he befriends her in the fifth book. Luna's relationship with Hermione, however, may be a closer example of this trope—Hermione bases everything on logic, Luna on faith, and by the end of the fifth book Hermione has learned to stop arguing about Luna's imaginary animals and conspiracy theories.
- A good thing, too, since most or all of her imaginary animals turn out to be real and most of her conspiracy theories turn out to be accurate, just usually misunderstood and often romanticized.
- Played with in A Man Called Ove. Parvaneh, Jimmy and the rest certainly have an effect on Ove but he remains much the same person throughout the novel.
- Special Agent Zane Garrett goes through this in Cut And Run. First happens with his new partner, Ty Grady, but then expands into the rest of the Grady family and Ty's old Marine Recon team.
- In Bird Taylor has to deal with Mimi, Elle, Heather, Charnel... All the while her power allows her to sense their true natures is it any surprise that she comes to show compassion for them?
- Freakin Gensokyo devotes some time to the Odd Friendship between the spirited hero Brad and the po-faced yuki-onna Genkan. Genkan finally admits that her time with Brad is bringing her out of her shell in Chapter 84.
- Shrek has a lot of this happen to him, with Donkey being the primary loony friend.
- Cars, Lightning Mcqueen starts to like Radiator Springs after being around all of the crazy characters.
- Finding Nemo: Very much the case with Marlin, though not all the loonies are nice (well, Bruce the Shark would be all right if he wasn't having withdrawal issues)...
- Tim from Dinner for Schmucks after hanging around with Barry.
- Claude from Hair epitomizes this trope.
- The Fisher King. The "stiff guy" is a shock radio host, but he's still quite stiff. And the looney is...well...Robin Williams. As a crazy homeless guy. It's a surprisingly serious movie, but still, you can see where this is going.
- Subverted in The Cable Guy, where "Chip" at first seems like a quirky but fun guy who helps Steven learn to loosen up and live a little, but Steven soon discovers that his new buddy is rather creepy, manipulative and even dangerous. Then he tries to end his friendship with "Chip," and things get even darker.
- Played straight in Guardians of the Galaxy, where exposure first to Peter Quill and then to each other makes Gamora, Drax and Rocket all loosen up.
- In The Avengers (2012), Bruce "the Hulk" Banner only starts to come out of his shell when Tony "Iron Man" Stark starts teasing him - mostly because Bruce's...impressive anger management issues mean that people tend to walk on eggshells around him a lot, and Tony is treating him like a person, not an unexploded nuke that happens to be able to talk.
- Jeff Winger grows (slowly and with much backsliding) from Jerkass to Jerk with a Heart of Gold when forced to interact with his unwanted study group. See especially the episode "Paradigms of Human Memory."
- Deconstructed in "Studies of Advanced Movement", when Annie — a similarly stuffy and uptight character (while hardly the Only Sane Man) — is moving in with Troy and Abed, the show's primary source of wacky hijinks, and is advised to be flexible with them. After an increasingly trying and stressful first day of putting up with their antics, however, she snaps and delivers an angry lecture about how unfair it is that she always has to be the one to adapt to their personality quirks while they seem to show no intention of attempting to accommodate her. They reach a compromise, and in a later episode Troy mentions that part of the reason they wanted her to move in was so that she would tone them down. Of course, the reason Troy brings this up is because Annie has accidentally turned Abed into Batman, so it's kind of a mixed bag.
- This is the basic plot of Nobuta Wo Produce.
- In Kamen Rider Fourze, Kengo starts out as an antisocial prick. By his eighteenth birthday party, hanging out with the quirky Kamen Rider Club has made him mellow out considerably—he even credits them with this transformation. Every other character save for Gentarou and Yuuki (they're already the looniest members of the cast!) has gone through a similar, if quicker and less drastic, transformation.
Tomoko: "I think you've become more human."Kengo: "With such egotistical club members around me, it's only natural to change. But...being more human probably isn't so bad."
- The X-Files: Agent Scully, who is friend (and more) with fringe theorist Agent Mulder. A rare case where the person improved is a woman.
- Castle, another example where the improved person is a female, in this case Kate Beckett, a no-nonsense police detective/Broken Bird, whose life is ultimately changed for the better (although it takes her the better part of four seasons to see it) by the sudden arrival of a goofy, metrosexual man-child novelist named Richard Castle.
- Squall in Final Fantasy VIII is a classic example. He's a very down to earth SeeD member who likes to focus on the task at hand. Unfortunately for him he's forced into dancing at a graduation ball by a Manic Pixie Dream Girl. And things just keep getting stranger from there.
- Paine from Final Fantasy X-2 is to some degree a female version of Squall. She's been reserved ever since the horrific event in which she was split from her Crimson Squad teammates Nooj, Gippal and Baralai after the investigation of the Den of Woe. The defeat of Sin at the end of Final Fantasy X has led Rikku to fully unleash the bubbly side of her personality, and Rikku's influence has largely led Yuna to embrace this as well. Throughout the game, they slowly begin to draw Paine out more and more.
- Ensemble Stars!: Given the number of Cloud Cuckoo Landers in the game, this is almost an overarching theme. However, it's most obvious with Tori (in terms of his interactions with Wataru and several of the first years) and Izumi (in terms of his interactions with Knights, particularly Leo).
- Susan in El Goonish Shive, thanks to her friendships with the rest of the main characters, but especially with Tedd, has grown from a Straw Feminist Deadpan Snarker to a nicer Defrosting Ice Queen.
- Roy in The Order of the Stick at first distrusts and disrespects Cloudcuckoolander Elan, but he later comes to admit how much knowing Elan has improved him as a person and as a leader.
- Sticky Dilly Buns has a relatively mild version with Ruby; aside from Dillon's clearly conscious attempts to activate the Gay Best Friend and Manic Pixie Dream Girl tropes, Zii talks her out of some of her repression, Angel expands her horizons a little, and Ramona reassures her that sex needn't be terrifying.
- Interestingly inverted for Emergency Exit's Bob. He needs crazy friends (especially Eddie) to keep him stable; without them he starts getting erratic and even silly. And the crazy adventures they go on are indirectly responsible for a serious decline in his mental health.
- Twilight Sparkle in the premier of My Little Pony: Friendship Is Magic is made a better pony of sorts when forced to make new friends, some of whom are definitely bizarre. Given the Aesop setup of the show, and some visible Character Development, all six ponies trade this trope around with each other.
- For fifty-two straight episodes of Avatar: The Last Airbender (out of sixty-one), Zuko is a moody jerk. Being forced into a "life-changing field-trip" with Manic Pixie Dream Boy Aang calms and brightens him enough to interact with people without shouting over the course of a single episode. Much of his issues are recovering from the trauma of breaking with his insane father and sister, leading to an identity crisis.
- The episode "It's a Wonderful Afterlife" paints this as Lydia's pre-series backstory, explaining that it was her relationship with Beetlejuice which enabled her to become the confident and outgoing person she is in the show.
- The entire arc of Wander over Yonder is rooted firmly in this concept: the dippy Wander attempts to befriend the villainous Lord Hater in the hopes of making him renounce his evil ways. Season 2 reveals that Wander has been doing this for years, targeting various baddies and reforming them through The Power of Friendship. Examples range from Hater's former idol Major Threat to Wander's own best friend and traveling companion Sylvia, formerly a bounty hunter hired to capture him.