They haven't seen each other in 80 YEARS.
Our hero or heroine meets someone who they seem to be sharing a number of traits with. The story progresses, and they find themselves working together, at cross-purposes, or drawing together romantically
And then — The Reveal
. The reason our hero has found that other person uncannily
familiar or compellingly attractive is that the new person is a Long Lost Relative they may never have known they had, or had believed gone forever. Variations include blood siblings
, aunts, uncles
, cousins once removed, and so forth. This trope is an integral part of the plot in stories where Everyone Is Related
Often this is hinted before it happens - thanks to Super Powerful Genetics
members of the same family usually share a number of trademark traits and habits that you can easily spot them by.
Once reunited, the reunited relatives may form a Brother-Sister Team
or join up with the rest of their Badass Family
, since blood is Thicker Than Water
See Family Twists Index
for more subtropes.
Subtrope of Connected All Along
Fair warning. Since this trope involves finding out about long lost relatives — it's rife with spoilers!
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Anime and Manga
- Sket Dance dropped a shocking yet somehow logical bombshell when it was revealed that Bossun and Tsubaki are twins tragically separated at birth. Before The Reveal, several characters commented on the similarities between the two.
- A subversion in Speed Racer. Racer X knows he's the long lost brother, but no one else does. This is also true in The Movie, wherein they made a plausible explanation for it because movie Speed wasn't quite as
stupid innocent as his anime counterpart.
- To Love-Ru has Kurosaki Mea who claims to be Yami's little sister. Considering they have similar traits (Shapeshifting abilities, assassins, from outer space and being Expies from Suou and Eve respectively) the claim has a little backup.
- Slayers plays with this; Word of God confirmed that Lina's first traveling companion, the flaky Naga the Serpent, is in fact Gracia Ul Naga Seyruun, the first princess of Seyruun and the long-lost sister of one of Lina's later companions, Amelia. They sort of meet three times in continuity: the Slayers Evolution-R anime had Naga's soul trapped in a suit of armor and became an ally for the group for five episodes, ''Slayers Premium'' had Amelia be blasted away before Naga appeared, and the radio drama following the movie had them briefly meet, but Naga simply told Amelia (who didn't recognize her) that she was a friend of Lina's.
- In Dino Breaker/DICE, Jet Seigel's brother Zack carbon-copies Racer X pefectly - he fakes his own death, then returns under the guise of Phantom Knight, with only his driving skills clueing Jet (and the audience) in on who he is.
- Dragon Ball Z kicks off with the dual revelations that Goku A) is an alien and B) has a much stronger evil older brother.
- More than a decade later, the new Dragon Ball Z special gives Vegeta a brother as well. His brother, however, is younger and much weaker, and apparently Vegeta knew of his existence already.
- In Fullmetal Alchemist, it turns out that the Big Bad is kind of Ed and Al's elder brother, since he recognized their father as his father, back before he pulled From Nobody to Nightmare, and turned Hohenheim into a monster, too. Complicated by the fact that this 'son' was also kind of his mentor, giving him a name instead of a number and teaching him to read.
- This relationship means that the homunculi are all technically Ed's nieces and nephews. But no one makes anything of this within the series.
- Even when Ed and Al first meet Father, he fixes them up since they're his precious human sacrifices and is fascinated to discover that they're Van Hohenheim's sons and Hohenheim is still alive after all these years, but doesn't therefore think of them in even vaguely familial terms. He seems to restrict those completely to his children; he also doesn't address Hohenheim as his father. Ed and Al return this lack of regard, though since they don't view the flashbacks they may never actually see it put in these terms.
- Genetically, since Hohenheim was his only parent, once he gets a body Father is Hohenheim's Evil Twin, making him also arguably the brothers' uncle. When he crosses the Bishounen Line during the finale, he gets described as 'the one who looks like Fullmetal without the automail', although he's actually prettier and has somewhat different hair.
- The relationship between the brothers and the homonculi was referenced at one point near the end when Pride, his philosophers stone exhausted and body crumbling, attempted to take Ed's body as the reason it was possible was due to that relationship. They're a very creepy family.
- In the 2003 anime version, this is not the case, though during the climatic final battle, it's revealed that the homunculus Envy is the resurrection-attempt of the son of Dante and Hohenheim, making him sort of Ed and Al's half-brother (as much as Sloth is their mother), depending on how much was retained in the bringing-back-to-life process. Exactly why he looks like Hohenheim's current body, given that Hohenheim is a Body Surfer, despite being centuries old is anyone's guess.
- Mahou Sensei Negima!: If the source is reliable, it has been confirmed that Asuna and Negi have a common ancestor in the Lifemaker.
- Char Aznable and Sayla Mass from Mobile Suit Gundam are brother and sister; though they've been separated for years, they instantly recognize each other when they accidentally cross paths in the second episode. Thus, "Long Lost Little Sister" is often considered one of the defining traits of a Char Clone, as seen with Zechs Merquise.
- In Tokyo Godfathers: first Hana and her "mother" (though she's not a blood relation), then Gin and his daughter.
- In Seto no Hanayome, it's revealed that Masa is Akeno's older brother.
- In Chance Pop Session, Akari, Yuki and Nozomi all meet at Kisaragi's music school, not only becoming friends, but harmonizing together well enough to become a successful pop trio, only to learn they are all long-lost sisters, and that the woman who trained them is their mother!
- In Fairy Tail, during the Edolas Arc Happy unknowingly running into his parents while escaping from the Exceed.
- Rave Master has main villain Lucia recruiting a number of demons and high profile criminals to beef up his army. Among the new recruits are, unbeknownst to him, his step-brother and grandfather. The grandfather elects not to mention this. Whether or not Deep Snow ever approaches Lucia about their semi-siblinghood is both unknown and unlikely.
- In Future GPX Cyber Formula, Osamu is Asuka's older brother, who ran away from home 5 years before the original series takes place to be a racer in England, and he uses a disguise to protect the team that she's in.
- In Nadia: The Secret of Blue Water, it's revealed that Emperor Neo is Nadia's older brother, Venusis, brought back to life as a cyborg.
- In Saiunkoku Monogatari, it is revealed that Shi Seiran, the retainer (but practically an adoptive brother) of the protagonist Shuurei's family, is the exiled prince Seien, the much admired and missed second eldest brother of Emperor Ryuuki.
- In Naruto, we have Tsunade and Naruto. Hundreds of chapters after their initial meeting, it is eventually revealed that Naruto is connected by blood with Tsunade. Tsunade is one of the only two last living blood relatives Naruto has. (The other is Karin)
- In Street Fighter Alpha The Animation Ryu meets a boy named Shun who says he's his younger brother.
- In Kill la Kill, it's revealed later on that Ryuko Matoi is Satsuki Kiryuin's younger sister, who was used in experiments with Life Fibers as an infant and tossed away when her mother Ragyo believed her to be dead.
- Baron Helmut Zemo leader of the Masters of Evil once took the identity of Citizen V as part of the Masters plot to pretend to be a team of heroes called the Thunderbolts. As Citizen V Helmut claimed that he was the grandson of the golden age Citizen when in fact Helmut's father Heinrich had killed the golden age Citizen V. Helmut was certain the original Citizen V had no descendents. A few years later Techno (worst friend ever) plays a prank on Helmut that pays off when Helmut gets decapitated by Scourge. Helmut finds himself in the body of the man who actually is Citizen V's grandson and Helmut has to go through a similar imposture all over again.
- After dying, the Marvel version of Captain Marvel has acquired a few offspring. Hulkling was from a fling he had with the Skrull princess Annelle. Mar-Vell's lover Elysius used Mar-Vell's genetic material after his death to impregnate herself with Genis and then she sped up his aging process. When Genis rebooted the universe one change in the timeline was that Elysius did the same thing a second time and had a daughter named Phyla.
- Cloak from Cloak & Dagger had a twin sister named Anna. We were never given much details on why she wasn't raised with Cloak and his other siblings and if Cloak even knows he has a twin sister.
- In Power Pack we are introduced to a man named Mr. Raymond. It is never fully confirmed who he is but it's strongly hinted that he is the Golden Age superhero Toro (who was presumed dead) and the father of Nova (Frankie Raye) who was a herald of Galactus. In the meantime a past version of Toro has come to the present and Frankie was thought dead, before she returned.
- Reed Richard's father Nathan supposedly has at least 3 other kids thanks to his time traveling adventures. He went to an alternate earth and married a woman named Cassandra and had a unnamed son with her, that son is supposed to be Kang's ancestor. Nathan tells his daughter-in-law Susan that he had once fathered a child with a Latverian woman and a horrified Sue jumps to the conclusion that Reed's arch-nemesis is also his half-brother but it turns out Nathan was referring to Doom's adopted son Kristoff. Huntarra was raised in alternate timeline with her half-nephew Franklin Richard/Psi-Lord, she later tells him she is Nathan's daughter and thus his aunt.
- Immortal Iron Fist's father Wendell Rand married a K'un Lun woman named Shakari and had a daughter with her named Miranda. Miranda's mother was killed by the H'ylthri and a distraught Wendell returned to earth where he eventually married Heather Duncan and shortly thereafter they had Daniel. Miranda would later take on the identity Death Sting.
- Llyra originally passes Llyron off as her son with Namor. This is later found out to be a lie but Llyron's true father turns out to be Namor's half-nephew Leon. Turns out Namor's father Leonard had a son with a human woman named Lawrence Mc Kenzie who fathered Leon (Black Moray) who fathered Llyron.
- Silver Surfer discovered that his father Jartran Radd fathered an illegitimate child named Fennan Radd after the death of Norrin's mother Elmar. It's unclear if this is actually true as Zenn-La was retconned as being destroyed by the Other and recreated as an illusion to comfort the Silver Surfer by Galactus.
- Charles Xavier has an Evil Twin sister who he didn't know about, who says he tried to kill her in the womb.
- Raven from Teen Titans finds out she is not the only living child of the demon Trigon. She discovers her father Trigon mated with six other women giving her the younger half-brothers Greed, Gluttony, Wrath, Lust, Envy and Sloth (Raven represents Pride). Post-Flashpoint Raven has 3 older half-brothers via Trigon named Belial, Ruskoff and Suge. When Trigon was first introduced it was implied that over the ages he has had hundreds of children but they had been killed by his enemies.
- Orphan twins Northstar and Aurora did not know they were twins until they were recruited into Alpha Flight. After their parents death Northstar went to live with distant relatives who adopted him while Aurora was raised at a strict Catholic all-girls school.
- Polaris is un-retconned and re-revealed to be the daughter of Magneto thus she is the half-sister of the Scarlet Witch and her former X-Factor team mate Quicksilver (and their dead sister Anya).
- Professor X also hid the existence of Cyclops and Havok's younger brother, Vulcan.
- Since his introduction in the 1960s is full of Fridge Logic (if Cyclops had been visiting Havok all along, what was the point of: A) keeping his existence a secret from all of his friends, and B) not telling Havok that they were mutants?) Alex Summers is usually introduced as Cyclops's long-lost sibling in newer adaptations (X-Men: Evolution, for example).
- In some continuities, Gambit is the third Summers brother.
- X-Man Storm has no siblings, but she does have a long lost branch of her family on her mother's side that was RetConned into existence to help justify her going back to Africa so she could marry the Black Panther.
- A subversion occurs with other X-Men: Longtime teammates Nightcrawler and Rogue are step-brother and sister.
- Although the trope was also played fairly straight with Nightcrawler's half-brother Graydon Creed (the non-mutant son of Mystique and Sabretooth). Rogue also has a few "adoptive" relatives on the side of her other mother, Destiny, including young X-Man Blindfold.
- In the New 52 continuity, Green Arrow discovers that he has a younger Japanese half-sister named Emiko Queen.
- Satana Hellstrom may count, though when her brother Daimon (Son of Satan) Hellstrom finally met her again, she was kinda sorta mistaken for being on the other side. (And weirdly, even though they hadn't met since being separated as young children, he'd previously had hallucinations about her with her correct current appearance and costume.)
- Spider-Girl (Mayday Parker), last we saw her, still was not aware that Darkdevil is her cousin (son of her father's clone).
- In some continuities, Aquaman has a long lost brother in Orm, aka Ocean Master.
- In Adèle Blanc-Sec: Le Mystère des profondeurs, Adèle's little sister Mireille, who not only looks like her but dresses very similarly, with the same taste for ugly hats.
- During the "Elegy" story arc of Detective Comics, it's revealed that Batwoman's nemesis Alice is actually her twin-sister Beth, who had been kidnapped as a child and believed dead. This revelation is not taken well.
- In Marvel Comics, Ka-Zar, Lord of the Jungle, is the long lost brother of deadly pirate the Plunderer, a fact initially only known to the Plunderer himself.
- One cartoon Charles Addams did for the The New Yorker shows two identical men, with identical inventions, sitting side by side in a patent attorney's waiting room. The caption: "Separated at birth, the Mallifert twins meet accidentally."
- Dwayne Taylor the first Night Thrasher of the New Warriors finds out that Donyell aka Bandit is his half-brother. What makes this really odd is that there had been a previous story where Dwayne and Donyell's father Daryl had been commanded to marry and mate with one of the Daughters of the Dragon's Breadth Cult by Tai but he refused on the ground that he was already happily married to Dwayne's mother.
- Prior to the Crisis reboot Wonder Woman had a twin sister named Nubia who was stolen by Mars, the God of war, after creation.
- After the events of the Marvel NOW! relaunch, Iron Man learned he secretly had an older brother named Arno Stark.
- More Fan Fiction than you can shake a rolled-up newspaper at. Long Lost Siblings are always crawling up out of the woodwork.
- More Harry Potter fanfics than you can count feature Harry's long-lost sister, Mary Sue Potter.
- A lot of Animorphs fanfics feature Tobias's long lost sibling, usually his sister. It was parodied in one fanfic; Tobias complaining about having to take of so many siblings.
- A lot of Phineas and Ferb fics are about this, nearly always the missing biological parents. "First Contact A Gemini Story", on the other hand, is one about Ferb's long lost twin sister.
- Used frequently to justify Copycat Sues
- Having Mulder's sister turn up is common in The X-Files fanfics. One troper read one in which it turns out Monica Reyes started life as Samantha Mulder, and is sure that one wasn't unique.
- These were as common as grains of sand in the early days of the Sailor Moon fandom. They'd almost universally be either Usagi or Mamoru's long-lost sister, though once in a great while Usagi would have a brother (since apparently she doesn't get enough grief from Shingo) or one of the other senshi would suddenly sprout a sibling or two. What was particularly odd with Usagi's many sisters was how often they were her older sibling, but were still usually banished (and thus forgotten by everyone until after the canon series) for breaking the "one heir" rule. Because it makes perfect sense to banish the firstborn for being an extra child.
- Justified example in the Detective Conan fandom. This is a popular fan theory for Detective Conan's lead Kudo Shinichi and his foil and Worthy Opponent the Kaitou Kid. (Who had his own very brief manga series before Aoyama started Conan and folded Kid into it.) Generally they're either twins and don't know it, or first or second cousins, but there have been considerable variations.
- This is all based on the fact that they canonically look ridiculously similar, when seen in 'normal' form. Interesting meta-use of Only Six Faces, since what the manga-ka actually did was use the same basic design for two heroes and then Lampshade it—specifically, by showing that Kid, a Master of Disguise who usually relies heavily on Latex Perfection, can dress as Shinichi without a mask. Just has to change his hair and body language.
- Wasn't that just in some of the movies? Those are canon, though.
- The backstories fans produce for these Epileptic Trees can be epic. One nightmare scenario from a world where they had been Separated at Birth had them not having been Separated at Birth, and instead raised by the Black Organization as evil Single-Minded Twins.
- The big reveal in the Rise of the Guardians fanfic Guardian of Light: Pitch is the biological father of the main character, Helen, who was taken into the future by Bunny on the day of her birth in order to protect her. Oh, and her biological sister is Mother Nature.
- Hivefled; Gamzee and Feferi turn out to be siblings Separated at Birth, and Gamzee is hanging around with the ghost of Sollux's centuries-dead half-sister who is also his and Feferi's half-sister on the other side of the family.
- When Elden meets Mrs. Bones in A Far Green Country, Elden learns that Mrs. Bones is really Elden's lost sister Beorna.
- Star Wars, natch.
- Luke and Leia are twins, and meet when one (farmboy from a backwater planet) rescues the other (political prisoner on the Death Star) with neither being aware of who they are.
- Obi Wan Kenobi was mentioned to have a brother, the original idea being that Owen "Luke's uncle" Lars was Obi-Wan's brother, not Anakin's.
- And Gunn Yage is Cade Skywalker's half-sister in the comics, making this trope In the Blood. Makes me wonder if when Luke and Ben reach the Fallanassi leg of their journey, they'll discover that Akanah has a child.
- In the Scream trilogy, Sydney Prescott's mother Maureen is killed by the original Ghostface killer before the events of the first movie. The Ghostface killer in the 3rd movie turns out to be Roman Bridger the son Maureen gave up for adoption. He was conceived when his mother Maureen was gang raped at a party and his father is presumed to be John Milton who was the producer of the Stab movies which were based on Gale Weather's book about the original Ghostface killings.
- The Addams Family is kind of an inversion. Fester is returned to the family by a con woman who thinks he's not the real long-lost Fester, brother of Gomez. But he is. Only with Trauma-Induced Amnesia.
- There have been a few variations on this with twins who were Separated at Birth, such as The Parent Trap and Twitches.
- Zorro The Gay Blade has a Separated at Birth sitch with Bunny Wigglesworth. Bunny knows they're brothers, but Diego hadn't known he had a brother.
- Diego did know he had a brother. But he hadn't seen his brother in years since Bunny had been in the Navy. Also, Bunny's birth name was Ramone and Diego wasn't aware that he had changed his name.
- Spock's touchy-feely half-brother Sybok in Star Trek V: The Final Frontier.
- Penny Priddy was the unknowing long lost twin sister of Buckaroo Banzai's wife, Peggy. Tragically, the sisters never had the opportunity to meet.
- Arnold Schwarzenegger and Danny DeVito portray the titular long lost brothers in the comedy film Twins. In an unusual departure from the twin trope, they are fraternal twins.
- Cameron Vale and Darryl Revok in Scanners. Revok is trying to get Cameron to join him, but when the reunion comes, they kill each other with Psychic Powers. Probably.
- Raymond from Rain Man.
- In the Robin Hood retelling, Robin Hood: Prince of Thieves, Will Scarlett ends up being Robin's half brother, related through their father.
- In the movie Soapdish, soap opera costars Lori and Jeffery nearly kiss before Celeste breaks them up to reveal that Lori is his daughter. Ew.
- In Desperado, El Mariachi and Bucho are brothers.
- In Scaramouche, the villain is revealed to be the hero's half-brother.
- Will Turner's father Bill in Pirates of the Caribbean: Dead Man's Chest.
- Just like Star Wars, Halloween II (1981) used it as a major plot point. In the previous movie, Michael Myers, the homicidal maniac, remained an unknown menace: no face and no real motivation behind his crimes. But as his very first victim happened to be his elder sister, when an explanation was needed about the murders, the former storyline changed "totally": Laurie Strode, the final girl, was not just any stalked babysitter. She is Myers' younger sister, born only two years before he stabbed the other one, and who was adopted after her parents' death in a car crash. Since then, movie after movie, it's quite clear that Myers only dreams of one thing: murdering each and every member of his family (and their friends, as there wouldn't be enough blood if he didn't slice and dice a dozen idiotic teenagers every year).
- X-Men: Days of Future Past: Screenwriter Simon Kinberg confirms that Magneto is Quicksilver's father, so the trope is played with in this case because although Erik suspects that Peter is his son after the teen mentions that his mother once knew a guy who could control metal, the older mutant doesn't try to seek out the truth or inform anyone else about the potential blood relation.
- Feirefis, Parzival's Moorish long-lost half-brother and ancestor of Prester John is only one of several long-lost relatives in Wolfram von Eschenbach's epic poem Parzival where Everyone Is Related.
- The titular character in Sir Apropos of Nothing discovers he has a long lost sister, not quite in time to escape Brother-Sister Incest, but at least to escape marrying her. Unfortunately, he doesn't tell her, which results in her hating him for dumping her so unceremoniously.
- Harry Dresden discovers fairly early in his adventures that he has a long lost half-brother, Thomas.
- As of Changes, he now has a long lost daughter and grandfather as well. It's complicated, as it also makes Ebenezar Thomas's long-lost grandfather as well, but neither know about the other yet, and Maggie doesn't know about any of her living relatives. Actually, it seems Harry is the only person who knows the whole family tree.
- The Baudelaire siblings encounter two of a set of triplets in A Series of Unfortunate Events — the third triplet is a Long Lost Sibling who eventually reunites with his brother and sister.
- Arthur Spiderwick is the long lost Disappeared Dad of The Spiderwick Chronicles. The same is true for The Movie.
- In the first book of The Obsidian Trilogy by Mercedes Lackey and James Mallory, Kellen Tavadon finds that Idalia, the person who nurses him back to health, is his sister (and that their father gave him Laser-Guided Amnesia to avoid bothersome questions from a six year old).
- The Kite Runner reveals that Hasaan is Amir's half-brother in a climactic reveal.
- In Havemercy Thom eventually realizes that Rook is his brother, leading to a lot of protest among fans who insist that their UST is undeniable (and it really is....)
- Something like this happens in The Black Fleet Crisis of the Star Wars Expanded Universe. In one of the two ultimately pointless major plotlines, Luke meets a woman who claims to be close friends with his mother. Apparently a lot of people claim that kind of thing, but he believes this one, since she's Force Sensitive. But she's part of a sect of extremely strict Actual Pacifists and she gives him a bunch of Secret Tests Of Character to see if his mother would approve of him, and since Luke readily uses weapons to defend himself and her, he fails all of them. And then it turns out that no, she was lying about knowing his mother and apparently just wanted a chance to moralize on Luke.
- Old Kingdom series: Turns out Sabriel has a half-sister, which is a very good thing considering that neither of her kids is Abhorsen material.
- The Molly Moon series is full of these. In the course of four books, Molly goes from having no family at all to discovering her mom (Lucy), dad (Primo Cell), her evil uncle (Cornelius), twin brother (Micky), and half-siblings through adoption (Sinclair and Sally Cell)
- The Mortal Instruments:
- Valentine Morgenstern is Clary’s biological father.
Jace and Clary end up being siblings... though not before they've sort of fallen in love with each other. Oops...
Once you get to City of Glass, you find out that Jace and Clary aren't related, and that Clary's actual brother is Sebastian.
- Amatis Herondale to Luke, more or less, although it's more of the fact that they're estranged siblings and Luke's afraid that she'd blame him for her divorce.
- The Heroes of Olympus:
- In this Percy Jackson and the Olympians sequel series it is discovered that Jason is Thalia's little brother. And no, not just because they share the same father. They're actual, full-blooded siblings.
- Hazel is Nico’s sister and Frank turns out to be a descendent of Poseidon, so Percy and Tyson adopt him as their brother.
- Leo is related to Sammy Valdez, Hazel's boyfriend from back during World War 2—specifically, he is Sammy's great-grandson.
- Heracles & Chrysaor to Jason and Percy. They try to kill each other.
- In Ender's Shadow (the parallel novel to Ender’s Game) we find out the backstory of Bean, a super-smart little genetic experiment who was kidnapped as an embryo, escaped captivity as a baby, and made it to the orbital battle school as a small child. He managed to forge a real friendship with exactly one other person in the school, who turns out to be the son of the people whose embryo was stolen, meaning Bean sought out and befriended his long-lost brother.
- Jessie Shimmer finds out she has multiple long lost relatives her father Ian and her older brother Randall in Shotgun Sorceress.
- In The Vampire Diaries: Midnight it is revealed to Meredith Sulez, by her parents no less, that she has a twin brother who was kidnapped by Klaus when she was just a baby. She also discovers that she is a type of vampire with kitten teeth.
- Played to a ridiculous level in the Wuxia Demi Gods and Semi Devils with the protagonist's father, Duan Zhengchun, being a big case of The Casanova. Every single Love Interest his son, Duan Yu, meets in his journey turns out to be his half-sisters. Though this is subverted later on as Duan Yu isn't Zhengchun's son, thus resulting in Duan Yu marrying all of them.
- In the eleventh Haruhi Suzumiya light novel, Fujiwara claims to be Mikuru's younger brother. The alleged sibling denies it, but the two of them seem to have some history together, though the versions of them we see are from different timelines.
- In Jane Austen's Love and Freindship, Laura lucks on her grandfather, followed by a positive cascade of discoveries.
- Jerin and Princess Ren in A Brother's Price find out that they are third cousins, sharing great-great-grandmothers. His grandfather was thought to be lost by family, but instead had been abducted and married to his grandmothers. This relation is distant enough that it does not hurt the romance, and in fact the Royal Blood that Jerin thus possesses means it's possible for them to marry.
- In Scaramouche, the villain was the hero's father.
- In The Lost Years of Merlin, Emrys (i.e., Merlin) first gets a Luke, I Am Your Father from Stangmar in the first book, and in the second finds out that his friend Rhia is his sister.
- In The Five Little Peppers and How They Grew it turned out that the Pepper children's mother and the husband of their rich benefactor's housekeeper were cousins.
- In Empire Of The East, the Lady Charmian's long-lost younger sister is unknowingly serving her as a handmaiden. Each of them lost their memories of the other as the result of encountering a demon as young girls. Well, "encountering" might be too mild; their father gave them to it as his pledge of loyalty- the demon allowed them to live for its own reasons...
- The plot of Fort Hope largely revolves around the protagonist, Greg, trying to get to know his long lost relatives. His love interest also ends up learning about relatives that she never knew she had.
- In Doctor Zhivago, Yuri Zhivago learns that his deadbeat father had an illegitimate son with Princess Stolbunova-Enritsi named Yevgraf. Later on, Yevgraf ends up being an important but enigmatic character, helping Yuri and his loved ones to escape most of the chaos brought on by the Russian Revolution.
- First Light: Peter and Thea are cousins. Peter's mother left Gracehope years earlier before coming back.
- In Shadow of Her Sins Alinadar, who was enslaved by pirates at the age of six, meets an older brother she didn't remember she had.
Mythology and Religion
- Classical Mythology: Oedipus, long-lost son of Laios (whom he kills) and Iocaste (whom he marries). A pattern repeated with Telegonos, son of Odysseus and Circe. He winds up accidentally killing his long-lost father, and in a creative instance of Pair the Spares, he marries Odysseus' widow Penelope, while Penelope's son Telemachus marries Circe.
- Morgan le Fay to King Arthur, who comes with extra disturbing quotient in the form of their mutual child he just sort of forgot about.
- Siegmund and Sieglinde find this out at the end of the first act of Die Walküre. This does nothing to avert Brother-Sister Incest.
- A Funny Thing Happened on the Way to the Forum: Miles Gloriosus and Philia. Thankfully revealed before their arranged marriage can take place, let alone be consummated.
- An interesting aversion of sorts in Into the Woods, where the baker and Rapunzel are these, but neither realizes and nor does their being related have any effect on the plot.
- The Mysterious Man also counts since he hasn't seen The Baker since he was a baby/toddler. However, he does affect the First Act unlike his daughter.
- At the end of the opera Il Trovatore an old gypsy reveals to the villain that he has just killed his long-lost brother. Since this is the last line of the libretto (and there are just 2 bars of music left to go), the baritone is reduced to making a face at the audience to express his dismay as the curtain comes down. And this troper has seen some truly ridiculous grimacing. Verdi must have been under deadline pressure.
- Played for laughs in Cox and Box, where the absence of a strawberry mark on his left shoulder proved that Box was Cox's long-lost brother.
- Apollo and Trucy in Apollo Justice: Ace Attorney
- Oh boy, Trials and Tribulations. In the last case not only do we find out that victim Elise Deauxnim was Mia and Maya Fey's long-lost mother (and Pearl's aunt), but serial killer Dahlia Hawthorne is Morgan Fey's long-lost daughter and Pearl's half-sister...as is Dahlia's twin sister Iris.
- The Masked Man in Mother 3. Though, really, if you didn't see it coming...
- Soulcalibur: In Soulcalibur V, Xiba and Leixia are half-siblings. Xiba is the result of an affair between Xianghua and Kilik, while Leixia is the daughter of the Ming emperor; Xianghua married the latter per her family's request after finding out of her affair with Kilik. As of right now, neither of them know their relationship.
- In Final Fantasy IV, Golbez is Cecil's long-lost brother.
- In Final Fantasy V, Faris is Lenna's long-lost sister.
- In Final Fantasy IX, Kuja, the game's main antagonist, turns out to be the long lost brother of our intrepid hero, Zidane. This drives a great deal of the game's plot.
- In Tales of Symphonia, Kratos is Lloyd's father. Until Lloyd was seventeen Kratos basically thought he was dead.
- Almost everybody with a sibling in Fire Emblem: Blazing Sword seems to have been separated, but Rebecca and Dan/Dart are the ones who fit this trope best.
- Also, Arthur and Tinny in Seisen no Keifu. And Leif and Altenna in the same game. In both cases, the latter has to be convinced by their brother to do a Heel-Face Turn. Finally, we have a particularly sad case with Leen and Corple, who don't even know they're brother and sister.
- In Radiant Dawn, Micaiah is the long-lost older sister to Sanaki, and is thus also lost to their grandmother Misaha, and thus, lost to the PROGENITOR of their line Lehran AKA Sephiran, since he thought Micaiah had died. This example is unusual in that the revelation doesn't impact the story at all; by the time it comes out, the game is over and both sisters have accepted that the other has their own country to protect, but promise to work together as friends and allies. Other examples in the same world include: Leanne to Reyson in Path Of Radiance, then Rafiel to both in Radiant Dawn, Rajaion and his nephew Soren to the Dragon Laguz Royalty in Radiant Dawn, and Ena to her grandfather Nasir in Path Of Radiance, as the sequel makes it clear it's been a while since they last saw each other.
- K' and Sarah/Whip in The King of Fighters.
- A mix of Luke, I Am Your Father and dead big brother happens with Valkyria Chronicles II, when Avan and co. was desperately trying to defend the school from Rebel forces, a Heroic Sacrifice by Juliana reveals that Leon is Dirk Gessernel, one of the three Gessernel siblings.
- In Sid Meiers Pirates, you can purchase maps that lead to where your long lost sister is hidden on a plantation. Once you have rescued her, you can also find your long lost father, mother, brother, cousin, etc. They might give you a map that leads to lost Aztec treasure!
- Heavily implied in the first Rune Factory game. Ivan is operating under the impression that you're his long lost brother, but doesn't act on his suspicions so that you can be happy.
- Non-protagonist example: In Rhiannon: Curse of the Four Branches, it turns out that the guy you exchange e-mails with is the long-lost son of a previous victim of the curse, who is reunited with his sister (off-screen) if you succeed.
- Subverted (!) with Ivan in Golden Sun and Golden Sun: The Lost Age. In the first game, he makes the acquaintance of spiritual leader and martial-arts master Hama, who acts as a mysterious mentor figure and refuses to bond closely any more than is needed to teach him to Reveal illusions. In the second game, Hama is revealed to be Ivan's sister... but neither one was lost to begin with: Ivan was sent away to be raised by non-Adepts so he would be in the right place at the right time to join Isaac's quest, and Hama has been discreetly keeping tabs on him the whole time, while pushing him away to keep her emotions from causing trouble. He's annoyed at this point, because she's the only blood relative he has, he wants to learn more about his past/family/etc., and she's still pushing him away because his destiny isn't done yet.
- Team Fortress 2 has Gray Mann, long lost brother of Redmond and Blutarch Mann and third son of Zepheniah Mann. When he was born, he was somehow perfectly fluent in English. This disgusted Zepheniah, and he wanted him killed, but Gray was abducted and raised by an eagle, who later in his life he killed and ate before going back to civilization to build his empire. 150 years later, he murdered his brothers and plotted to destroy Mann Co. with his robot army, leading to the "Mann Vs. Machine" game mode.
- In Homeworld the Kadeshi are this to the Kushan on a species-wide level...which is discovered after their fleet and habitat ships are decimated.
- Disgaea Dimension 2 introduces Laharl's younger sister Sicily and Etna's older brother Xenolith.
- Sicily is introduced by retconning Laharl's mother death - she still died after giving ger mana to cure Laharl's illness, but she was pregnant with Sicily and had the choice to become an angel, but Sicily wouldn't survive, or pass the angel bliss to Sicily, but dying in the process.
- Xenolith is introduced revealing that Etna was actually born with a immense magic power inside her that would lead to her death, but her older brother decided to merge himself with a magic-absorbing artifact to take most of Etna's own magic, so she could survive. He then left Etna to Krichevskoy's care.
- The inciting villain of Avencast: Rise of the Mage and the player character spend so much time opposing each other, the reveal that they're siblings is hardly a surprise.
- Hoo boy, Ever17. Of the people on LeMU, Sara and the Kid are fraternal twins. And they're the children of Tsugumi, on LeMU at the same time, and Takeshi, who's the other main character.
- Trudy and Sharon in General Protection Fault
- Blue and Isaac in Namir Deiter - Blue was four years old when their mother kicked his father out. Issac didn't know about his other sister, Roxanne (who had already left home when the elder Deiter met his father). They've since all gotten to know each other.
- Girl Genius has Zola la Sirène Dorée who was heavily implied (good resemblance) to be a relative of Lucrezia and thus Agatha. And eventually was revealed to be Lucrezia's niece.
- Zeetha was implied to be Klaus' daughter, and by extension Gil's sister.
- Theo and Agatha found out early on that they are cousins. Theo was very happy about the revelation, since he has no other living relatives.
- Homestuck: John and Jade are Half-Identical Twins, as are Rose and Dave, and they were split up via the Reckoning. This reveal had the side effect of sinking two of the biggest ships in the fandom.
- In Glorianna, Hope is Glorianna's daughter, abandoned as a baby and Raised by Orcs to be a fanatical cultist.
- In El Goonish Shive, hints are increasingly being dropped that Susan and Diane are this, since they're physically identicalnote and were born 20 minutes apart on the same day.
- Kevin & Kell's Corrie was eventually revealed to be the long-lost daughter of Ralph Dewclaw.
- Double subverted with Anak and Androssi Zahard from Tower of God. At first they seem like adoptive sisters, but then it turns out that Anak is not a real Princess of Zahard. She is the rumored daughter of Androssi's sister. Meaning that Anak is Androssi's niece even though Anak is older
- Mickey Mouse - Remember Oswald the Lucky Rabbit? You probably don't. He's Mickey's long-lost older half-brother. Walt Disney created him before Mickey, and he laid the groundwork for Mickey's rise to stardom. Disney ultimately addressed Oswald's return in the video game Epic Mickey.
- The Secret Saturdays - Drew yoinks off the helmet from VanRook's apprentice, gets a look at his face, and has a flashback which makes her realize he's her brother, which leads to his Heel-Face Turn.
- There's also Homer's brother Herb in The Simpsons.
- Who was raised in an orphanage run by Dr. Hibbert's long-lost brother. In Round Springfield it was then revealed that Bleeding Gums Murphy was the long-lost third Hibbert brother.
- Homer also has a long-lost half-sister in England.
- The Simpsons Spin-Off Showcase: "And did someone say, 'long-lost triplets?'"
- Hank of King of the Hill was revealed to have a Japanese half-brother.
- From the standpoint of every other toon on The Warner Lot, Animaniacs Yakko, Wakko and Dot are Long Lost Siblings. But the truth is they were locked in the water tower because they're completely nuts.
- Motor Ed turns out to be Dr. Drakken's cousin in the first episode of season 3 of Kim Possible. Not so much a long lost sibling as a wish he were still lost cousin, but it still counts, especially after Drakken starts taking Motor Ed's fashion advice.
- 4Kids editing of Winx Club provides an example of this trope being undermined by editing: The Trix exposit about the Dragonfire to Bloom. Of their ancestors' attempt to take it, they say, "Your sister ruined everything by saving your life." This prompts Bloom to say, "Daphne?" But in the dub, the Trix never mention this, instead referring to Daphne as "the guardian of the flame", with Bloom saying "Daphne?" being cut out. It's rather awkward, since the first time it's indicated that they're sibs in the dub is when she's looking at her family tree in S2.
- In a post-Poof episode of The Fairly OddParents, it turns out that Cosmo and Jorgen von Strangle are cousins, and that fact was kept a secret for obvious reasons. Bonus points if you throw in Talking to Himself, since both characters are voiced by Daran Norris.
- In Family Guy, Lois has a long lost brother Patrick who was put in a mental hospital.
- Kevin's stepfather shows up in the finale for season 1 of Ben 10: Ultimate Alien — he's been with Kevin's mother since the Ben 10 days, but this is the first time he appears onscreen.
- The Christmas Episode of Hey Arnold! features the reunion of Mr. Hyunh and his long-lost daughter.
- He-Man happens to have a twin sister from whom he was Separated at Birth. Hordak attempted to kidnap them both due to a prophecy but was only able to get Adora. This backfires when Adora, learns her true heritage, does a Heel-Face Turn and becomes She Ra Princess Of Power.
- Hank Venture from The Venture Bros. finds out that his best friend Dermott Fictel is the illegitimate son of his father Rusty Venture and Nikki Fictel. Nikki Fictel was a teenager when Dermott was born and Dermott was raised to believe Nikki was his sister and his grandmother was his mother. Hank finds this out shortly AFTER losing his virginity to Nikki but has his memory wiped.
- Eric Cartman from South Park finds out his old ginger nemesis Scott Tenorman is his half-brother in the episode 201. Eric had previously orchestrated the murder of Scott's parents (and thus Eric's own father) and tricked Scott into eating their remains at the Chili Con Carnival. When Eric finds out he becomes depressed...at the thought of being half-ginger, though he does cheer up when he realizes he's also half-Denver Bronco.
- In Donkey Kong Country, the Christmas Episode reveals that Klump's long-lost brother is Captain Skurvy, who was exiled from their family home when Klump created a firework accident and Skurvy took the fall.
- TNMT (2012): It turns out Miwa a.k.a. Karai is this to Splinter. The Shredder took her in on the night of her mother's death, making Splinter believe his wife and daughter both died.