Sibling Yin-Yang

"After 30 long years, finally, the two of us meet. The brother of light...and the brother of dark."

- Liquid Snake, Metal Gear Solid

In real life, siblings hardly ever act the same. Fiction sometimes takes this to an extreme.

Enter Sibling Yin-Yang, the occurrence of siblings that are nearly polar opposites. If he's cool and reckless, she's responsible and thoughtful. If she's a spiky-haired hooligan, he's the nerdy wimpy one. If he's an immature brat, she's... well, you get the picture.

The even more extreme form leads to Polar Opposite Twins, or even Evil Twin. When this leads to complete antagonism, it becomes Cain and Abel. See also The Glorious War of Sisterly Rivalry and Tomboy and Girly Girl. If an Aesop is involved, chances are it's a case of Foolish Sibling, Responsible Sibling.

Anime and Manga
"Riku: We have absolutely nothing in common!
 * Al and Ed from Fullmetal Alchemist.
 * The anime and light novels also have Fletcher and Russel Tringham, who present many parallels with the Elric brothers.
 * So much so that not only do they impersonate the Elrics at least twice, there's a certain amount of Sibling Yin Yang between respective imposters-the Tringhams fulfill a certain amount of the expectation of what you're going to get with the Elrics, which is quite different from what you actually get. Aside from the fact that each Tringham has an ego that matches his respective Elric.
 * Not to mention Alex and Olivier Armstrong (manga and second anime only). Alex Armstrong, a.k.a. Colonel Clean, is the almost grotesquely overmuscled poster boy for Pec Flex and prone to fits of staggering overacting at every possible opportunity, often with Manly Tears, and he's actually a total softy. His older sister Olivier is a Badass Normal of epic proportions, a slim, Magnificent Bitch Social Darwinist Lady of War who can call Ed short without him even trying to argue and has no compunction about killing representatives from Central because they irritated her and pushing their bodies into wet concrete.
 * To be fair to the Major General, she says he irritated her, and by that means he confessed proudly to being involved in a soul-stealing murder conspiracy that amounts to betraying the whole country, and tried to take her men away.
 * Tiff and Tuff in Kirby of the Stars.
 * Kyou and Ryou in Clannad; Kyou is a violent Tsundere, Ryou a shy Class Representative.
 * Interestingly enough, Kyou is also class representative in her class.
 * Same deal with Kagami and Tsukasa (respectively) from Lucky Star
 * To further the suspicions of an Expy / Kyo Ani Shout Out, Tsukasa has a very similar hairstyle to Ryou. With the same hair color to boot.
 * Mermaid Melody Pichi Pichi Pitch uses it repeatedly. Caren is a brooding, grudge-holding Broken Bird, while her twin sister Noel is a forgiving, self-sacrificing Yamato Nadeshiko. When Caren got nicer and, as a result, dropped Out of Focus, she became a loud party girl to keep the opposite dynamic going. There's also . Lucia and Nikora, though only posing as sisters, fit it too with The Ditz versus the Team Mom. In fact, it's even lampshaded in the Black Beauty Sisters, who are also definitely not sisters.
 * Miki and Kozue from Revolutionary Girl Utena.
 * In Lucky Star, Konata lampshaded two pairs: Kagami / Tsukasa and Yui / Yutaka. Konata hypothesized this trope is caused by one sibling absorbing attributes from the other sibling.
 * Well, Kagami and Tsukasa have different eye shapes.
 * Taken out of context by Minami, who says that Miyuki Takara must have absorbed something else from her, by virtue of being next door neighbors
 * Light and his sister in Death Note. Their only common points are that they are both good-looking and respected. She is a nice, ordinary person, he is a freakishly intelligent Well Intentioned Extremist with sociopathic tendencies and a god complex.
 * Also Near and Mello, when you consider that they were raised side by side.
 * Twin examples: Risa and Riku in D.N.Angel; Vash and Knives in Trigun; Abel and Cain in Trinity Blood; Metatron and Sandalphon in Angel Sanctuary; in Chrono Crusade; Suboshi and Amiboshi in Fushigi Yuugi. Also note that as is often the case for the twin archetype, which some scholars view as a sub-category of the hermaphrodite archetype (seriously), one twin is gendered more 'feminine' (Risa, Vash, Abel,, arguably Metatron) and the other more 'masculine' (Riku, Knives, Cain, , Sandalphon). (This has nothing to do with sexual orientation!)
 * This trope is even lampshaded by the twins in D.N.Angel:

Risa: Nothing at all!"


 * Another twin example: Yoh and Hao from Shaman King. Hao is an evil twin.
 * Soma and Kanna from Devil & Devil, Soma is a weak ocult otaku and kanna is a violent rebel, it doesn't help that they each get possessed by the devil Sword and the angel Ios respectably.
 * Yoh and Minatsuki in Deadman Wonderland are an interesting case: both are liars, cowards, and opportunists, but Yoh may be fundamentally a caring guy while his sister is a Yandere.
 * Jun Ushiro and his sister Kana in Bokurano. She is sweet, shy and forgiving, he is violent and brooding.
 * Yoh and his sister in High School Debut.
 * On that note, Akito and his sister fit the bill as well.
 * Tetsunosuke and Tatsunosuke in Peacemaker Kurogane.
 * Hansel and Gretel in Ludwig Kakumei... somewhat.
 * Anna and Johan in Monster. Anna is outgoing, compassionate, helpful and an idealistic humanist. Johan is quiet, introspective, manipulative and an utter sociopath.
 * Yuki and Ayame in Fruits Basket. Ayame is the Always Camp Aloof Big Brother, while Yuki is the White Prince with an Instant Fanclub. Yuki doesn't find Ayame very bearable, while Ayame insists he's showing support for his younger brother. He really doesn't get it.
 * In Hajime no Ippo, there's Kumi Mashiba, Ippo's main love-interest and a Yamato Nadeshiko to boot. And then there's her big brother, Ryo 'The Executioner' Mashiba, an angry and brooding boxer who eagerly uses intimidation-tactics and fouls to beat down his opponents, and just generally comes across as a borderline psychopath. About the only person who's NOT scared of him is Kumi, who have been known to slap him to the floor when he got out of hand.
 * Yuma and Yuna Kashiwagi from Pani Poni Dash. Yuma is an extreme extrovert (and borderline Yandere), Yuna is an extreme introvert. Yuma goes so far as to actively sabotage Yuna's attempts at being more accepted just to keep eyes on her.
 * The Chizeta princesses from Magic Knight Rayearth: Tarta the younger is loud, rude, and Hot Blooded while Tatra the elder is quiet, polite, and a total pushover (apparently), which is probably why the younger sister seems to be the leader.
 * Ikki (rough, aloof, Jerk With a Heart of Gold) and Shun (gentle, Martial Pacifist, selfless) in Saint Seiya
 * Also Saga (thoughtful, wise, just ) and Kanon (selfish, scheming, arrogant  )
 * In Axis Powers Hetalia, North and South Italy fit this trope; North Italy is ditzy, cheerful, and friendly, while South Italy is more reserved and unfriendly, especially towards North Italy's partner in crime Germany and his ex-caretaker, Spain. Switzerland and Liechtenstein also fit this trope, with Switzerland being a moody gunslinger and Liechtenstein being a gentle and kind Token Mini Moe.
 * Also, America and Canada: The first is a loud, outgoing mix of Eagle Land archtypes and Boisterous Bruiser; the second is much more quiet, sensible, and overlooked.
 * Germany and Prussia, too. Germany being a Perpetual Frowner Neat Freak and Prussia being a Hot Blooded Jerkass.
 * Ukraine and Belarus fit as well. Ukraine is a sweet, sensitive, hardworking Bokukko Naive Everygirl with big melons, and Belarus being a creepy, Stalker With a Crush Elegant Gothic Lolita with Yandere tendencies. Russia, on the other hand, is another story.
 * Let's not forget Netherland and Belgium. He's a brooding Tsundere with a Scarf of Asskicking and a penchant for smoking, she's a tomboyish and cheerful Cool Big Sis with a Sweet Tooth.
 * China with any of his siblings, but most seen when he interacts with his adopted brother, Japan
 * Nove and Wendi of Magical Girl Lyrical Nanoha, the inseparable red-headed duo amongst the Numbers sisters,, with Nove as the always angry one and Wendi as the always happy one.
 * Kouichi Kimura and Kouji Minamoto of Digimon Frontier. Aside from being twins, the holders of the spirits of Light and Darkness, and having the entire Separated At Birth thing going for them, there's even an episode named "The Brothers Yin and Yang."
 * The Nitori siblings of Wandering Son couldn't be more different. Big Sister Maho is outgoing and pushy. Little Brother Shuichi is timid and even feminine. This actually gets lampshaded by the pair's father, who relates to Shu a story of their grandmother betting Maho would be a boy and Shu a girl before they were born. Given the family's recent discovery of Shu's issues, Nitori Sr. wonders if Grandma was really so wrong about them.
 * Hot Blooded Fiery Redhead Apollo and Defrosting Ice Queen Eerie Pale Skinned Brunette Artemis in Cyborg 009.
 * Shinkyoku Soukai Polyphonica has the Yugiri sisters. Persete is the outgoing one, Prinesca is the shy one.
 * Ace and Luffy on One Piece. Ace is more level-headed and polite than his brash and bordering on brain-dead little brother. Even Luffy's crew have expressed disbelief at how different Ace is from their captain.
 * And then we have
 * Fran and Veronica Madaraki of Franken Fran were outright made to be this. Fran was made to preserve life (which can lead to unpleasant results); Veronica was made to end it (which she prefers to do swiftly and painlessly, though often gratuitiously). Fran tries to put Veronica more on her side of the scale, but so far, no dice.
 * Paul, from Pokémon, and his brother Reggie.
 * Fuka and Fumika Narutaki of Mahou Sensei Negima. The former's the trouble-making class pankster while the latter's constantly worried about how the former's pranks will get them in trouble as she gets dragged along.
 * Much like Luffy and Ace above, Yui and Ui Hirasawa of K-On! are a Cloudcuckoolander and mature young lady respectively.
 * Umehito Nekkozawa and his younger sister Kirimi from Ouran High School Host Club. He's dark, brooding and extremely photosensitive, while she's cheerful, outgoing, and hates dark places.
 * The twins have some of this as well, although only when they are separated. Hikaru keeps the trouble-making personality (with some added Tsundere) whereas Kaoru is much more mature.
 * Shion and Mion from Higurashi no Naku Koro Ni. Shion is more laidback and polite then her tomboyish twin sister.
 * Black and White of Tekkon Kinkreet. Black is violent and territorial and White is childish and innocent. The fact that they need each other to balance out the pair is repeated often throughout the film and becomes a plot point.
 * The Tomokanes--both without a name--in GA Geijutsuka Art Design Class. The younger Tomokane is a Bokukko, while her elder brother is an frail Non Action Guy. This is lampshaded when the younger Tomokane's class teacher first saw the older Tomokane, and commented how the two's characters complement each other.
 * This trope was also Invoked in this case, as the younger Tomokane's personality was shaped as a response by her brother constant mental bullying and exploiting his Ill Boy status to avoid punishment.
 * Minatsu and Mafuyu Shiina in Seitokai no Ichizon. Minatsu is busty, loves sports and isn't afraid to speak her mind. Mafuyu is petite and quiet.
 * Keroro Gunsou has the Hinata sibings, unassertive bookworm Fuyuki and bossy tomboy Natsumi. Even their names contrast, containing the kanji for "winter" and "summer" respectively.
 * They're not actually related, but Tengen Toppa Gurren Lagann's Simon and Kamina were definitely designed to fit the trope -- Simon is shy, relatively sensible, quiet and intelligent, where Kamina is outgoing, reckless, big-mouthed and something of an idiot. Their respective appearances couldn't be much more different, either; Simon is short (prior to the Time Skip, anyway), pale and skinny with dark purple hair and blue eyes, where Kamina is tall, tan and muscular with bright blue hair and red eyes. Finally, in case all of that wasn't quite unsubtle enough, their names also contrast: Simon's name comes from "shimo", the Japanese word for "below", and Kamina's name comes from "kami", the Japanese word for "above".
 * Amanchu has Ai and Makoto, the former being a somewhat violent Genki Girl in contrast with her meek, thoughtful twin brother.
 * Karin and Yuzu Kurosaki of Bleach.
 * Code Geass has the proud and xenophobic Lady of War Cornelia li Britannia, and her little sister, the self-deprecating Wide Eyed Idealist Euphemia li Britannia.
 * Heiwajima Shizuo and his brother Kasuka in Durarara. Shizuo's a violent maniac with unbelievable physical strength, while his brother is extremely taciturn and doesn't seem to show any fear of his brother's temper or power. Their relationship is actually very healthy, if low-key.
 * Suiseiseki and Souseiseki from Rozen Maiden are very much this, both including a Tomboy and Girly Girl relationship, but with several more differing characteristic traits. Where Souseiseki is stoic, Suiseiseki is emotional. Souseiseki is serious and collected, while Suiseiseki is mischievous. Souseiseki believes it is the duty for every doll to participate in the Alice Game regardless of personal attachments, while Suiseiseki strictly opposes the Alice Game due to fear of losing her sisters.
 * Both leading families of B Gata H Kei have this dynamic. Yamada is an energetic Covert Pervert who has little on her mind but sex. Her younger sister Chika is much more level-headed. Takashi Kosuda is shy but thoughtful, expressing himself through his camera. His older sister Kazuki is outgoing, boyish and shameless within her own house.
 * Raoh and Toki from Fist of the North Star: one of them is a merciless conqueror and the other is a messianic healer.
 * Samui of Naruto is stoic, calculating and very serious at all times. On the other hand, her brother Atsui is Hot Blooded, rash and a reckless loudmouth. To drive the point home, their names mean Cold and Hot respectively.
 * The Sasuke and Itachi dynamic plays with this. As a child, Sasuke strived to be like Itachi to earn recognition, but his brother was always several steps ahead. After the Uchiha massacre, Sasuke tried to distance himself from Itachi and become different from him, even refusing to obtain power in the same way as his brother. However, after, Sasuke drastically changes, becoming driven by hate and revenge against anyone who would stand against him, unlike his brother, who was motivated by Ironically, Sasuke would have ended up very similar to Itachi, had the latter not traumatized him in the way he did.
 * Future GPX Cyber Formula has Osamu and Asuka Sugo. Osamu is a calm, level-headed individual while Asuka is more energetic and cheerful. Franz Heinel and his younger sister Lisa counts as well.
 * Unsui and Agon of Eyeshield 21. Unsui is serious, responsible, hard working, and polite. Agon is arrogant, self-centered, sadistic, and lazy.
 * Masao and Sanae Kouda from Detective Conan look nothing alike. Sanae is a pretty Office Lady, Masao has a huge case of Face of a Thug. Despite this, the siblings are very close...
 * The Suzuki sisters, too. Older sister Ayako is a soft-spoken and mature Ojou, younger sister Sonoko is an outspoken fashionista.
 * Arago: Arago and Ewan. It's even highlighted by their hair color, one of the only visible difference between the two (the other being a scar on Ewan's arm).
 * Infinite Stratos has the Shinonono sisters, Tabane and Houki. The older is very silly, while the younger is very serious.
 * Kotetsu and Muramasa Kaburagi from Tiger and Bunny. Kotetsu is an impulsive, Hot Blooded, dorky as all hell Ascended Fanboy superhero, whereas Muramasa is his down-to-earth, low key, responsible older brother who runs the family liquor store.
 * Mobile Suit Gundam has Sayla Mass and Char Aznable. She's a hero, he's a villain. She's loyal to the core, he has Chronic Backstabbing Disorder. She's got a boatload of Ship Tease with Amuro. He wants Amuro's head on a pike. She doesn't want Revenge for their father's death, Char is consumed by the need for it. She's naturally empathetic, Char suffers from Lack of Empathy. The two of them have absolutely nothing in common, and are on opposite sides of the war, yet somehow avoid Cain and Abel.
 * The show also features the Zabi siblings who manage to be a four man version of this. On the one side you have antivillains Dozle and Garma. Both take care of their men, love their significant others, have passionate attitudes, and respect their father, sharing many personality traits despite their very different appearances (Dozle is The Brute, Garma The Dark Chick). Contrasting them are Gihren and Kycilia, a pair of manipulative, cold-blooded social climbers who believe that We Have Reserves, break the rules of war left, right, and centre, and make no real connections with anyone besides themselves (though Gihren is the worse of the two in this regard). Appropriately, Garma and Dozle quite like each other, while Kycilia and Gihren hate one another.
 * Gundam AGE has Zeheart Galette and Desil Galette. Zeheart's a pretty nice guy & cares about his friends despite his loyalty to Vagan. Desil on the other hand is an Ax Crazy Blood Knight who views soldiers, for Vagan and the Earth Federal Forces, as his own toys.
 * Otome no Iroha features Iroha and Hifumi as Masculine Girl Feminine Boy (respectively), prior to their Gender Bender.
 * Bakusou Kyoudai Let's and Go has a titular Seiba siblings. The older brother, Retsu, is level-headed and careful while the younger one, Go, is Hotblooded and reckless. Their traits show in their representative racing machines.
 * In Chrono Crusade we have Chrono and his Evil Twin Aion.
 * Rogue and Sting from Fairy Tail (who might not be related but were at least raised as brothers) are big on this. Sting uses 'white' magic, is always very in your face, shows interest in almost everything going on, and is only concerned with strength. Rogue uses 'shadow' magic, generally lets Sting do the talking, acts uninterested in evverything, and places value on comradery.
 * In Chrono Crusade we have Chrono and his Evil Twin Aion.
 * Rogue and Sting from Fairy Tail (who might not be related but were at least raised as brothers) are big on this. Sting uses 'white' magic, is always very in your face, shows interest in almost everything going on, and is only concerned with strength. Rogue uses 'shadow' magic, generally lets Sting do the talking, acts uninterested in evverything, and places value on comradery.

Comic Books

 * Charles Xavier and Cain Marko in X-Men. And that's before you get into how they are, respectively, the most mentally powerful and the most physically powerful people in the world...
 * Xavier also has Cassandra Nova, who literally exists to be his polar opposite in absolutely everything.
 * Suntop and Ember in Elf Quest.
 * Hawk and Dove from Justice League, who are also as different as Red and Blue.
 * Batman's two sons, Tim "Robin" Drake (adopted) and Damian al Ghul (biological), in recent comics. Tim is logical, cool-headed, and always follows Batman's example by never killing, while Damian is rash, violent, and thinks nothing of killing his enemies. They slug it out pretty much every time they meet.
 * You could extend that to Tim Drake and Nightwing (Dick Grayson). Nightwing can be logical, but he's more hot-tempered and his creation of 'Nightwing' directly extended from him rebelling against Batman. Tim and Dick act like actual brothers though, unlike Damian.
 * And then there's Dick Grayson and Jason Todd. Apart from the obvious (Dick is a hero, Jason is a villain, or at least a Nineties Anti Hero), Dick is acrobatic, fairly cheerful for a member of the Batman family, and indepedant from Batman. Whereas Jason relies more on weaponry, is dark and wrathful, and is almost pitifully obsessed with being seen as Batman's son true heir, if not replacing the Dark Knight himself.
 * The (otherwise unnamed) Two Brothers from Marvel vs. DC - one was the Living Embodiment of the Marvel Multiverse, the other was the Living Embodiment of the DC Multiverse. When they became (re)aware of each others existence, they each decided to destroy the other.
 * Spider Girl and her cousin/genetic half-brother . She's a naive, optimistic Plucky Girl who wears a bright costume. He's an angsty pessimistic Snark Knight dressed in dark tones. Together they fight crime! Sometimes.
 * Desire and Despair. Death and Destiny. Destruction and Dream. Delirium and... You know what, it's probably best just to leave it at: "The Endless".
 * Delirium and Delight.
 * Many examples in Clan Destine. The most prominent example is Jasmine/Cuckoo/Kay Cera and Walter Destine/Wallop. Then again, when their younger sister Samantha complains about their constant bickering, their father Adam attributes it to them being too alike. In a flashback, we also have Thaddeus and Albert, who seem to get on much better.

Film

 * Dash and Violet in The Incredibles.
 * Mary-Kate and Ashley Olsen in their movies.
 * Jamal and Salim of Slumdog Millionaire.
 * According to their Tech Specs Skids and Mudflap are this... with the caveat that they're both quite stupid. Skids merely believes he's the smart one.
 * A famous example, Mufasa and Scar from The Lion King, who are opposite in every extreme.
 * Since the reveal that is Austin Powers brother, they probably qualify.
 * Ian (Ewan McGregor) and Terry (Colin Farrell) in Woody Allen's Cassandra's Dream. Even just visually, the contrast between the brothers is striking, looking nothing alike axcept for being drop dead gorgeous.
 * Carefree, irresponsible David and woobish, frustrated Albert in The King's Speech.
 * Hotblooded Santino and cold hearted Michael in The Godfather
 * Happens naturally in Thor between him and Loki. Thor was a Boisterous Bruiser who took in the attention without realizing how self-descructive and reckless he was. Loki was the opposite, being quiet and prefers to use trickery and illusions to fight.
 * In Secondhand Lions, both Hub and Garth are Badass Grandpas who had many adventures in their lives, but in the end, Garth is the more calm, bookish one who could sit back an relax while Hub was looking for adventure and had no trouble beating up five punks after getting out of the hospital.

Literature

 * Li Han Ch'in and Li Yuan, sons of one of the T'ang Lords in David Wingrove's Chung Kuo
 * Discworld: Esme and Lily Weatherwax. Granny Weatherwax is the angry, bitter old woman who always saves the day because she feels she has to since her "good" sister Lily decided she'd rather be the evil one. It's especially frustrating to Esme because Lily isn't even particularly good at being evil.
 * Princes Peter and Thomas in  The Eyes of the Dragon by Stephen King (Peter is fit and raven-haired like their mother while Thomas is chubby and sandy-haired like their father).
 * Fablehaven has Kendra and Seth Sorenson. Kendra is smart, cautious, and thoughtful, Seth is arrogant, energetic, and brave to the point of stupidity.
 * Most sibling relationships in Harry Potter follow this to some extent, such as Sirius (hates his pureblood-obsessed family and eventually runs away from home) and Regulus (proud to be part of said family), Bellatrix (fanatically devoted to Voldemort) and Narcissa (secretly terrified of him), et cetera. Also, Harry's mother Lily (a muggleborn witch) and her sister Petunia (who is perfectly normal, thank you very much).
 * In even greater contrast to Bellatrix and Narcissa is their other sister Andromeda Tonks. Not only did she not become a Death Eater, she married a Muggle-born wizard, produced a daughter who became an Auror, and helps out the Order of the Phoenix, though she's not officially a member herself.
 * Long-lost siblings  from Havemercy, mostly because of their wildly different upbringing.
 * Lady Envy and Anomander Rake from The Malazan Book of the Fallen: She's The Vamp, he's a stoic Blood Knight.
 * The Izzies from The Merlin Conspiracy by Diana Wynne Jones play with this trope. At any given time, the two girls will take on polar opposite traits, for example one being rude and aggressive while the other is shy and fainting. Then, at random times, they'll switch roles. Twin girls in a magical family where only one can be selected to inherit the family's magic, this is their way of fighting back by making themselves completely indistinguishable.
 * Every sibling pair in The Moomins
 * Elinor - the sense - and Marianne - the sensibility, an archaic word for romanticism, in Sense and Sensibility.
 * Also in Austen, Pride and Prejudice contrasts intelligent, aware, Elizabeth with her pretty but vain and shallow sisters Kitty and Lydia, who are also compared to Jane, who is beautiful but also extremely sweet and loving, and all of the sisters are compared again with Mary, who is plain, austere and studious, yet stupid.
 * Persuasion fatures radically different Eliot sisters, Anne being friendly, pleasant, and down-to-earth, and her two sisters being selfish hypochondriacs.
 * Sansa and Arya Stark in A Song of Ice and Fire. They even look completely different (Sansa is a beautiful redhead like her mother, Arya is longfaced and darkhaired like her father.)
 * Also, the vicious Joffrey Baratheon and his gentler little brother Tommen.
 * Also, Stannis and Renly Baratheon.
 * The twins Jaime and Cersei Lannister seem to be very similar in A Game of Thrones, but when they start getting PoV chapters and character developement in the later books, they move towards this trope. It's particularly in terms of how much morality (and sanity) they retain in any given situation.
 * In the grey-and-black Yin-Yang category, large, muscular Emotional Bruiser Anti Villain Sandor Clegane and his huge unrepentant rape-and-murder-machine brother Gregor.
 * In The 39 Clues, we have Amy and Dan Cahill. Amy can be painfully shy and a bookworm, while Dan can be immature and goofy but is more daring and has a photographic memory. However, they make a great team.
 * Thom and Alanna in Song of the Lioness. Thom likes to do magic but hates swordplay. Alanna, his twin sister, likes swordplay but initially fears and detests her magic.
 * And in the Circle of Magic series, we have Daja's students, Nia and Jory Banacor. Nia is shyer and quieter, with woodworking magic, while Jory is louder and more outgoing, with cooking magic.
 * Leafpool and Squirrelflight in Warrior Cats, especially during The Second Series.
 * Connor and Grace of Vampirates.
 * The Star Wars Expanded Universe has Jacen and Jaina. Oddly, Jaina is more masculine than her brother.
 * Flonne and Ozonne of the Disgaea novels. Flonne is a nice, flaky, adorable and optimistic Otaku Love Freak, while Ozonne is grumpy, rude, boyish and snarky Money Believer. They can't walk a step without arguing with each other.
 * In Ayn Rand's Atlas Shrugged, we have Dagny and James Taggart, and Hank and Philip Rearden. Both sets of siblings hold polarized world views and that in turn shows us that blood is not Thicker Than Water.
 * Katniss and Primrose Everdeen in The Hunger Games. Katniss is tough, a tomboy, a hunter, has difficulty connecting with people, and resembles their father. Prim, meanwhile, is delicate, sweet, well-liked, a healer and Friend to All Living Things who resembles their mother. Despite this, the two are incredibly close.

Live Action TV

 * Claire and Lyle, as well as Nathan and Peter, from Heroes.
 * Hiro and his older sister Kimiko, with Hiro being idealistic, child-like, and bored by the prospect of being a businessman like his father; Kimiko is intelligent, motivated, and ambitious in regards to taking a place within the family's company.
 * Wizards of Waverly Place has Alex (a mischievous, prankish, lazy, reckless manipulative bitch) and her older brother, Justin (a calm, collected, studious, mature badass bookworm, bordering on mad scientist- mad because of Alex).
 * Sam's twin sister Melanie from I Carly. The former is almost permanently grouchy, borderline sociopathic, and sarcastic, while the latter is upbeat, outgoing, and perky.
 * Chuck and Ellie in Chuck.
 * Betty and Hilda and of Ugly Betty.
 * J.D. and Dan in Scrubs.
 * Sam and Dean in Supernatural. Also, Castiel and Gabriel. Later, Castiel and Balthazar.
 * Should be noted that Sam and Dean's relationship is a parallel for Michael and Lucifer's, who are ying yang brothers themselves.
 * Similar to the Clegane brothers example, Dexter who is morally ambiguous, and his brother who is...not.
 * Aunts Lily and Vivian in Pushing Daisies are both eccentric shut-ins, but the similarities end there.
 * The Booth brothers from Bones - Booth the elder likes his comfort zone while Booth the younger is flashy and much more upwardly mobile.
 * The Girls and the Boys from Jon and Kate Plus Eight (the somewhat bossy Girls take after their mother while the more laid-back Boys take after their father)
 * Megan and Lily in Privileged and, to a lesser extent, Rose and Sage.
 * Firefly: The Tams. Simon is cooler and calmer and more disciplined, and River is more sensitive and (for obvious reasons) more erratic. On the other hand, she is physically more powerful.
 * Numb3rs: Don is more "Jock-like" and Charlie is more "Geek-like".
 * In the first season of The Big Bang Theory, the twin sister of the gawky, socially awkward nerd Sheldon is revealed to be a gorgeous, statuesque Southern Belle.
 * Dick and Beaver on Veronica Mars. Dick is loud, stupid, sex-obsessed and borderline-sociopathic. Beaver is quiet, smart, reclusive and.
 * Joe and Brian on Wings.
 * The twin brothers in the "War Zone" episode of The Closer. One's an accomplished Army Ranger, the others a Complete Monster gangbanger.
 * Mad Men: Anna Draper, widow of the real Don Draper is free-spirited and warm. She has a sister who is sour and uptight.
 * Damon and Stefan in The Vampire Diaries. One is a Friendly Neighbourhood Vampire and the other is a Jerk With a Heart of Gold or Heroic Sociopath.
 * From the new BBC Sherlock, the Holmes brothers are portrayed this way. Sherlock is easily bored and implied to have as much predilection for starting crime than stopping it, if the latter was impossible. Mycroft runs a shadowy government agency and is a much calmer and more collected than his dramatic, wild brother. This is in contrast to the characters of the original books, where Sherlock was driven and really cared about what he called "his art," while Mycroft was terminally lazy and probably could have been even greater than his brother, except that he didn't care to be.
 * Identical twins Katie and Emily Fintch from Skinsat least in their first season. Katie is the leader, dresses like sex-on-legs and Really Gets Around ("I haven't not had a boyfriend since I was seven"). Emily is eternaly in her shadow, dresses slightly more concervative and falls in love and is monogamus. There is also the tiny little fact that Emily is a closeted Lipstick Lesbian and Katie is a raging homophobe whose favorite target is the girl that Emily has fallen for.
 * Aaron Hotchner from Criminal Minds and his brother, who appears for exactly one episode and is never mentioned again. Perhaps their prominence in the series is another way that they're opposites?
 * Pablo and Marcelina Guerra from Carrusel. Pablo is a loud The Prankster. Marcelina is a Shrinking Violet.
 * Charlie and Alan Harper from Two and A Half Men. One drinks, gambles, attracts the hottest women like moths to a bulb, and lives in a nice house overlooking the beach, while the other doesn't drink (on his best days, anyway), is socially awkward, and is pretty much hopeless with women... Oh, and he's also divorced, has a kid, and lives off his brother.

Mythology and Religion

 * In the Mabinogion: The brothers Nysien and Efnysien are complete opposites, one so kind and gentle he could bring warring armies to peace, and the other so wicked he could make the most loving family destroy each other. Their names even reflect this, meaning respectively "friendly one" and "hostile/enemy one." To highlight their differences, "Efnysien" also means "not Nysien."
 * Older Than Dirt: The Sumerian sun god Utu and his brother Nergal, god of plague and fire.

Newspaper comics

 * The Otterloop kids in Cul De Sac. Alice is a hyperactive attention seeker. Petey is anxious and quiet.

Tabletop Games

 * The Unconquered Sun and Luna, from Exalted. One is so absolutely perfect and virtuous that he imposes order on the world by his mere presence, and the other embodies chaos and change to such an extent that she doesn't even have a consistent Motivation. They weren't created at the same time, though, or one could say that they are literally Different As Night and Day.
 * Urza and Mishra in Magic the Gathering have a strong Red Oni Blue Oni dynamic: Urza is detached and introspective, while Mishra is hotheaded and outgoing.

Video Games

 * Rin and Len Kagamine from the Vocaloid (and Hatsune Mix) series.
 * Mario and Luigi of Super Mario Bros, thanks to Luigi's increasingly Divergent Character Evolution as a Lovable Coward over the last ten years.
 * Crash and Coco of Crash Bandicoot
 * Prometheus and Pandora of Mega Man ZX
 * Queen Tia and Jack of Mega Man Star Force 3
 * Iris and Colonel of Mega Man X are technically identical twins: as a developing single reploid, they couldn't handle the series' thematic Logic Bomb and split into Iris, compassion for all living things and Colonel, the willingness to kill without hesitation to protect and for peace. They were an attempt to replicate the titular X's ability to handle this paradox. They fact they failed to live up to these principles, even one at a time, causing may have originally foreshadowed
 * Bethany and Carver Hawke from Dragon Age 2 definitely count. Bethany is kind and supportive of Hawke, whereas Carver is surly and shares a rivalry with Hawke.
 * Starfy and Starpy of The Legendary Starfy.
 * Literally yin and yang in Final Fantasy IV with Cecil and . The two exhibit a good deal of emotional yin yang in Dissidia Final Fantasy.
 * Also, Palom and Porom from the same game.
 * Lightning and Serah from Final Fantasy XIII.
 * March and Salsa from Eternal Sonata, due to the game's light/shadow mechanic in battles, they are quite literally Different As Night and Day.
 * Lucas and Claus from Mother 3
 * Yun and Yang from the Street Fighter III series. Yun is loud and outgoing, while Yang is quiet and introverted. Also, Yun focuses on the strength of his attacks, while Yang focuses on the number of hits.
 * Hector and Uther in Fire Emblem: The Blazing Sword. Though this can probably be chalked up to the fact that Uther's functioned as Hector's father figure since their parents died.
 * The three Pegasus sisters are a rare trio example. Quiet, serious Fiora butts heads with boisterous Farina, who in turn gets a kick out of teasing both her and shy, sensitive Florina.
 * In Fire Emblem 6 we have another sibling trio... also of Pegasus sisters. Yuuno is a sweet Action Mom, Thite is a stoic Defrosting Ice Queen and Thany is a hyper Genki Girl. And there's also a set of twins: the cheerful mage Lugh and the snarky shaman Rai.
 * Unusual triplet variant, from Metal Gear Solid - Solid and Liquid Snakes are extremely diametrically opposed; reserved, guilty Solid lacks his brother's ambitious, manipulative nature, and passionate, vengeful Liquid lacks his brother's wisdom and emotional clarity. This is complicated by the arrival of the third triplet, the calculating, focused Solidus, who considers himself a 'perfect balance' of his brothers' traits - he's wise and manipulative at once.
 * The Scarlet Sisters: Remilia carries herself with class, which Flandre is a bit too, uh, energetic when "playing."
 * Even in Fanon, when she once joyfully pounced Marisa in a Christmas-themed fancomic after waiting impatiently in the basement for Christmas decorations to be finished, an audible CRACK is heard. Ouch!
 * The Komeji sisters as well: Satori is usually portrayed as being the calm and possibly deadpan elder sister with hidden emotional depths, while Koishi is usually portrayed as a very lively and cheerful girl who occasionally gets too energetic when hugging Okuu.
 * It gets better with the Komeijis. If you take an image of either of them and invert the colours, their clothes (and hair... mostly) will take on the colours of the other sister!
 * Netto (Lan) and Saito (Hub) Hikari from Rockman EXE/Megaman Battle Network, especially in the Japanese version. Netto is outgoing, brash, and rather hot-headed; Saito is more calm and collected.
 * The Kirishima siblings from Project Justice - elder sister Yurika is a quiet, timid Ojou Of War, while younger brother Kurow is a megalomaniac Psycho for Hire complete with a Slasher Smile.
 * Hisui and Kohak in Tales of Hearts. The elder is Hot Blooded and impulsive and rude, and even his speech is crass; his sister is soft-spoken and polite. There's also Croaseraph, who is an aggressive Dual Wielding Glass Cannon who wants to Destroy All Humans, and his brother Crinoseraph, a stoic, defensive spellcaster with two shields who's maintained his loyalty to his master.
 * Dante and Vergil embody this trope, and just about every other antagonistic sibling relationship ever created.
 * In Apollo Justice: Ace Attorney, Kristoph Gavin is a cool, businesslike defense attorney while his brother Klavier is a wild, extroverted prosecutor. Futhermore,.
 * And in the same game, there's
 * Ronny and Sally Dobbs of Backyard Sports. Tony and Angela seem like this, but they're both egotistical.
 * The Williams sisters from Tekken. Nina is statuesque, cold, and blonde while Anna is the curvaceous and flirty brunette.
 * Itsuki and Sayo in Suika. Itsuki is gentle, shy and a bit of a pushover. Sayo is brash, slightly tomboyish and aggressive.
 * Fyuria and Zerva in Record of Agarest War. Fyuria has light-based attacks, Zerva has darkness-based attacks. Together, they have a powerful Yin Yang Bomb.
 * Same thing with Lavinia and Faina.
 * Jeanette and Therese Voerman (AKA Tourette Voerman) from Vampire: The Masquerade Bloodlines. The Malkavian PC even describes them as "The Ivory Princess" and "The Ebony Princess" respectivly.
 * Subway Bosses Emmet and Ingo of Pokémon Black and White at the very least appear this way; Emmet wears white and is always seen smiling, while Ingo wears black and is constantly frowning.
 * Dark Souls has the Queen of Sunlight Gwynevere and the Darkmoon God Gwyndolyn.

Visual Novels

 * Twin example: Hisui and Kohaku from Tsukihime. Hisui is an introverted maid who is skilled at cleaning, but lousy at cooking. Kohaku is an extroverted maid who is skilled at gardening and cooking, but terrible at cleaning.
 * Also from the Nasuverse, Shinji and Sakura in Fate Stay Night. Subverted in that
 * There's also the Aozaki sisters; it's best to explain how they respectively react to meeting somebody with the Mystic Eyes of Death Perception. Aoko tells the user to respect the sanctity of life, but to also use his powers for what he believes in. Touko's reaction? "They're useful! Come work for me!" Touko hates Aoko, incidentally. Probably because Aoko keeps stealing stuff from her.
 * Twin sisters Torta and Arietta from Symphonic Rain who explicitly tried to make up for each others flaws.

Web Comics

 * Molly and Galatea in The Inexplicable Adventures of Bob
 * Elan and Nale from Order of the Stick. They even have opposite alignments (Elan is Chaotic Good, Nale is Lawful Evil).
 * From the Start of Darkness prequel, Redcloak and Right-Eye also count.
 * Oasis and Kusari in Sluggy Freelance. Kusari is emotionless and unfailingly loyal to Hereti-Corp. Oasis is an Ax Crazy Yandere who kills all Hereti-Corp employees on sight.
 * Angelika and Julie from Our Little Adventure. Julie is mature and responsible and Angelika is a nutcase.
 * Jack and Louise from Miscellaneous Error. Jack is batscat nuts, and his younger sister Louise is more straitlaced and responsible.
 * Elon and Myari of Ears for Elves, oh so much. Elon is cautious and methodical where Myari is impulsive and excitable.

Web Original

 * Lee and Toe in Kate Modern.
 * It's complicated to explain the relationships of kids of Homestuck, but they seem to do this:
 * Brunettes (John and Jade ): Naive, Adorkable with Nerd Glasses, forthright, and Jumped At the Call. John and   live in the suburbs while Jade and   live on isolated islands. John, Jade, and   have like certain genres more than others (bad movies (unironically), furry art/anime, and , respectively) while   loves all genres indiscriminately (but specially if they have  ).
 * Blondes (Rose and Dave ): Cynical, slightly Anti Hero with Cool Shades (for the guys), Genre Savvy/Properly Paranoid.
 * In as much as animal counterparts can be considered siblings: Bec is the "good dog, best friend" of his owner Jade while God Cat is owned by no one and seems much more ambiguous. They're the
 * The Troll kids (who are basically siblings) do this with their ancestors and each other. For example Vriska likes to torture the child-like Tavros and while they're both considered losers their ancestors were.
 * The Troll kids (who are basically siblings) do this with their ancestors and each other. For example Vriska likes to torture the child-like Tavros and while they're both considered losers their ancestors were.

Western Animation

 * Steve and Hailey in American Dad.
 * Bart and Lisa in The Simpsons.
 * Doug and Judy from Doug.
 * Dexter and Deedee in Dexters Laboratory.
 * Carl and Chloe in Carl Squared.
 * The aptly named Yin and Yang from Yin Yang Yo.
 * Carl and Herman too, with Carl's magic and strategy being contrasted by Herman's muscle and brute force. "Dojo Alone" showed that, if they ever worked together, they'd be unstoppable, but they can't stand each other.
 * Danny and Jazz in Danny Phantom. Danny is insecure, rash and powerful, while Jazz is book-smart, confident and collected.
 * Katara and Sokka in Avatar: The Last Airbender. Sokka is sarcastic, cynical and The Smart Guy, while Katara is the open, idealistic Team Mom.
 * Zuko and Azula are as different as red and blue.
 * And even Iroh and Ozai.
 * The Legend of Korra gives us Mako and Bolin - one's a broody, dark, Troubled but Cute firebender devoted to winning the probending league and protecting his little brother; the other's a boisterous, fun-loving, earthbending lady's man. Mike and Bryan must like this trope.
 * There is also Ikki and Jinora.
 * Starfire and Blackfire of Teen Titans.
 * Also Mas y Menos despite the fact that they're on the same side, and to a certain extent the thoughtful, pacifistic, somewhat clingy Thunder and hotheaded, independant, pyro/electromaniacal Lightning.
 * Ben and Gwen on Ben 10. Cousins, but close enough.
 * Riley and Todd from The Replacements.
 * on Re Boot. Ironiclly, both are the Evil Twin... in the beginning.
 * Huey and Riley in The Boondocks.
 * Yin and Yang from the Histeria! episode "Return to China".
 * Phineas and Ferb, in some ways, though their differences seem more complementary than opposed, given how close they are. (Technically they're stepbrothers, though even they never refer to themselves that way.)
 * For that matter, either/both of them with their older sister Candace.
 * Zack and Wheezi of Dragon Tales. Not only that, but they are also two halves of a two headed dragon.
 * Vicky and Tootie in The Fairly Odd Parents.
 * Daria and Quinn in Daria pretty much epitomize this trope. Somewhat subverted later when we learn that Quinn is actually reasonably intelligent.
 * Meg and Chris of Family Guy before Flanderization set in. They still both have it with Stewie.
 * Several sibling pairs in The Amazing Chan and The Chan Clan: Stanley and Henry, Suzie and Anne, Anne and Tom.
 * This is played up with Mario and Luigi even more in the Super Mario Bros Super Show cartoons. In the SMB3 Bully and either Kooky or Big Mouth seem to fit the trope.
 * Ang and Ling in Legend of the Dragon. Ang is an easy-going, self-effacing hero, and Ling is an intense, ambitious Anti Villain (later Anti Hero). She even gets her powers from "the darkest Yin".
 * Hank and Dean, the titular Venture Brothers, have grown to become this in later seasons. Dean is a nerdy, frail, non-confrontational Non Action Guy who is being groomed for a career as a super scientist, while Hank is an underachiever and wannabe Action Hero.
 * Princess Celestia and Princess Luna in My Little Pony Friendship Is Magic. Celestia, who controls the day, is gentle, motherly, and a bit mischievous, while Luna, who controls the night, is stern, overly formal, and a bit bad-tempered (as seen in "Luna Eclipsed"). That may be a side effect of being sealed in the moon for a thousand years, though.
 * The Daughter and the Son, from Star Wars:The Clone Wars are literal examples of this trope, as they are representing the Light and Dark Sides of the Force respectively.

Real Life

 * Christopher and Peter Hitchens. Christopher was a very outspoken atheist/anti-theist and held predominantly (but by no means exclusively) liberal political views. Peter is an Anglican convert from atheism and holds predominantly conservative political views. Granted, both are relatively high-profile journalists, but beyond similar vocations and genetics, the similarities generally end there.
 * Chris was known for drinking and smoking a lot, whereas Peter can't drink much and doesn't smoke. Plus, Chris supported the Iraq War, bucking the left-wing consensus, whereas Peter opposed it, bucking the... Uncanny.
 * George W. and Jeb Bush. Both are Republican politicians, true, but George is (by all accounts) a very personable man who parlayed his youthful love for the bottle and a certain white powder into a deeply-held religious faith. Jeb (by all accounts) is somewhat less personable (though not half as detached as their father), and seems not to be half as religious as his brother. Oh, and one is seen as being rather stupid (although some see this as Obfuscating Stupidity), and the other is quite intelligent and certified political whiz.
 * Not so sure about Jeb not being so religious. He is a high ranking member of the Knights of Columbus.
 * The Knights of Columbus are Catholic. George W. Bush is a born again Christian. It's a different sort of religious attitude, even if there's an equal level of devotion involved.
 * The Mitford Sisters. Two of them were Nazis Diana (who married Oswald Mosely, leader of the British Union of Fascists) and Unity (who was a personal friend of Adolf Hitler). Jessica on the other hand was a member of the Communist Party and civil rights activist. Nancy was a novelist, and Deborah is the Dutchess of Devonshire; Nancy was considered to be a moderate socialist, and Deborah a moderate conservative. Pamela was the only non famous sister.
 * Prim and proper Elizabeth Windsor vs. her sister, Princess Margaret the party girl. (Both are universally agreed, however, to be infinitely preferable to their uncle David).
 * Tom Skilling, the greatly respected Chief Meteorologist for WGN-TV and the Chicago Tribune newspaper, versus his brother Jeff, currently in a federal penitentiary for his actions as CFO of Enron.