Given a lampshade in Ashita no Nadja. Marianne is in love with a boy named Francis, who's in a Sibling Triangle since he and his twin brother Keith both love main heroine Nadja (who leans more towards Francis, but once was VERY strongly leaning towards Keith). Therefore she believes that Nadja should go with Keith, which would not only help Keith himself but would help her to get Francis's affections. She is so convinced of such a possibility that she even tells such things to Nadja herself.
Suzuna Ayuzawa, the younger sister of the title character in Maid-Sama!, is actively trying to invoke this on Shintani Hinata, a Hopeless Suitor for her sister and their mutual Childhood Friend. She succeeds.
A variation in Otoyomegatari occurs with a woman named Talas. In her culture, it is customary to marry your husband's brother if he dies before having children. Her first husband had four brothers, and each married her and died childless in succession until each one met an untimely end. Talas had to Settle for Sibling four times in a row.
Inverted in 'Nexus' as Dantetries to get June to settle for him after his brother disappears.
Film — Animation
In Princess And The Frog, when Charlotte le Boeuf can't get married to Naveen to fulfill her dream of marrying a prince, she (at least jokingly) toys with the idea of marrying Naveen's brother instead. He's six-and-a-half.
Film — Live Action
In the 1954 film of Prince Valiant, Sir Gawain hooks up with Princess Aleta's sister Ilene after Aleta ditches him for Val.
Played with in The Frisco Kid; the rabbi protagonist is arranged to be married to the daughter of a local Jewish merchant, without having met her; she's vain, selfish, a total flirt and obviously not a good match for him. Her shyer, more modest and withdrawn sister is a much better match... as the rabbi discovers when he eventually arrives in town, takes one glimpse of the younger sister and falls hopelessly in love with her, without having even met his intended bride. He ends up marrying her instead.
Happens at the very end of The Palm Beach Story, in particularly zany screwball comedy style as the twin sister getting married looks quite confused and isn't sure quite how she got to the altar (and neither do we).
Something like this happens in Like Water for Chocolate. Basic outline: Boy Meets Girl. Boy likes girl; girl likes boy. Girl can't marry because of cultural tradition. Boy can't be around her alone because of a restrictive culture. Boy marries girl's sister to be close to girl.
In Jane Austen's Persuasion, Charles Musgrove was once in love with the heroine Anne Elliot. She turned him down, and he married her younger sister. No bitterness seems to exist on either side.
Sense and Sensibility: When Edward Ferrars refuses to go through with his Arranged Marriage to Miss Morton, his mother disowns him and considers having her younger son Robert marry her (with no one but Elinor wondering how Miss Morton herself feels about this). Ironically, Edward's Clingy Jealous Girl Lucy, whose secret relationship prompted the feud with his mother in the first place, quickly leaves him in favor of his now much-richer brother, which is just fine as it leaves him free to marry Elinor.
The eponymous character from Clarissa suggests this to Roger Solmes, who wants to marry her, as her sister considers him a good man and Clarissa hates him with a passion. Her family treat this as a huge insult.
This is narrowly averted in Pride and Prejudice: Mr. Collins comes to town intending to propose to the eldest Bennet sister, Jane. Upon learning she is almost already engaged, he's content to settle for Elizabeth. When she rejects him, their mother hopes he will continue moving down the line and settle for Mary, but he ends up marrying Elizabeth's best friend Charlotte instead.
Though in a subversion, despite the quote above Laurie never actually attempted to use Amy as a Replacement Goldfish for Jo; they fell in love after Jo told him no.
In Tess of the d'Urbervilles, Tess knows she is going to die, so she makes Angel promise that he will marry her sister Eliza.
In the Outlander series of novels, A young priest dying of consumption marries his pregnant lover to his impotent brother while on his deathbed. The baby is the heroine's great-something-grandfather.
In Like Water for Chocolate, the hero wants to marry the heroine but is told that since she is the youngest daughter, she may never marry. So he marries her sister to be close to her.
In Harry Potter,Word of God says that George married Angelina Johnson, who had once gone on a date with his twin brother, Fred. Fred is dead by this point.
Inversion: Ron had a crush on Fleur (even more than most people), but she winds up with his oldest brother, Bill.
A variation happens in the short gothic story "The Romance of Certain Old Clothes" by Henry James. Two sisters fall in love with the same man. The man marries one of the sisters, who dies shortly after. He then marries the other sister. The story ends with the jealous ghost of the first wife exacting revenge on her sister.
In The Color Purple, Mr. initially had asked for permission to marry Celie's younger sister, but was denied by their father, so he marries Celie against her will instead.
Fathers and Sons by Ivan Turgenev: Arkady is at first interested in Madame Odintsov, but eventually goes for her younger sister Katya.
In North And South, Billy Hazard eventually grows disenchanted with Ashton Main's manipulative behavior and starts to see the beauty and goodness in her sister Brett. When he and Brett decide to get married, Ashton doesn't take it well and arranges to have him murdered on the way to their honeymoon.
In A Song of Ice and Fire, this appears to be accepted standard procedure in Westeros as most noble marriages are arranged for political purposes: any time a man dies before he can marry his betrothed, she is very likely to be betrothed to any surviving (unattached) brother he has.
Margaery marries Tommen after Joffrey is killed at their wedding.
Catelyn Tully is originally engaged to Brandon Stark. But after Brandon is killed by Aerys Targaryen, his responsibility to marry the Tully girl passes to his younger brother Eddard. This turns out to be a Perfectly Arranged Marriage, as they grow to be perfectly happy with each other and have a household of several children.
Littlefinger seems to be happy with Lysa Tully, as he can't have her sister Catelyn until he pushes Lysa out of the Eyrie. Keep in mind that the Eyrie sits atop one of the highest mountains of the Vale of Arryn. Later on he decides to go after the far more disturbing "Settle for Daughter" with Catelyn's daughter Sansa. Made even squick-ier by the fact that Sansa is posing as his daughter, under the false name Alayne Stone, by that point
In Warrior Cats, Berrynose was in love with Honeyfern, but Honeyfern died of an accident. Moons later Berrynose mated with Honeyfern's littermate, Poppyfrost.
An unusual variant from the Heralds of Valdemar series. Shortly after her father's death young Queen Selenay of Valdemar is charmed by Prince Thanel of Rethwellan and finds herself in a miserable marriage that ends when she is widowed in a "hunting accident"note his kinsmen knew he had died during the attempted assassination of his wife, but also knew him and were happy to sweep the matter under the rug rather than deal with the political complications. Some 15 years later Selenay met her late husband's younger brother Daren in person for the first time and they fell for each other on the spot.
In Rumer Godden's In This House of Brede, Larry wants to marry Elspeth Scallon, but she becomes a nun. He marries her cousin, Jean.
In Dune: The Butlerian Jihad, when Xavier thinks Serena is dead he marries her sister Octa.
Happens a few times in the works of V. C. Andrews. Examples include:
In the Landry series, when Ruby marries Paul Tate, Beau marries her twin sister Gisselle since he can't have Ruby.
Cutler series: Jed Booth wanted to marry Violet (Lillian's real mother), but instead married her sister because polite society dictated he should court the oldest daughter.
A variant in the Logan series. Cary is heavily implied to be in love with his twin sister Laura, so after she dies, he ends up with their cousin (second cousin, although they don't initially know that) Melody, whom everyone thinks looks like Laura.
In Poul Anderson's The Un-Man, Jeanne Donner is married to a man who, she does not know, is one of a great Brotherhood of clones. When he is killed in underground work, she is induced to leave her home with their son by another clone, passing himself off as her husband, before his killers capture them both. Later, having learned the truth, she tracks down the clone who rescued her, who had fallen in love with her. When he says he would get over it, she tells him she doesn't want him to.
A darker version occurs in New Tricks. It turns out that the victim's brother-in-law was the one who put her in a coma. As he "had a thing for Asian note South Asian, that is women" and decided if he couldn't have her, nobody could. He tried to make it look like a hate crime and then invoked this trope.
Mad Men: Anna Draper, upon learning from our Don that her husband (the real Don Draper) never mentioned her, she muses that he actually preferred her sister who "looked like her but had two good legs." Perhaps this is the reason she was so warm and welcoming to the man who stole her late husband's identity.
One episode of Two and a Half Men revealed that Alan had originally asked out his ex-wife Judith's sister then only dated Judith after she said no.
Initially played straight and then finally averted on General Hospital. Dr Monica Quartermaine was introduced on the show as the wife of Dr Jeff Webber. It was quickly revealed that she had once been engaged to Jeff's brother, Rick and only married Jeff on the rebound after Rick dumped her and then was promptly presumed dead in Africa. When Rick came Back from the Dead, Monica resumed her pursuit of Rick, but after he became involved with Dr Lesley Williams, Monica decided not to settle for staying married to Jeff and divorced him.
Helo was originally in love with Boomer, who was in love with Chief Tyrol. Helo fell in love with Athena, a copy of the same Cylon model as Boomer, when they were set up together by the Cylons on the planet Caprica, thinking that she was Boomer. Helo married Athena some time after learning the truth, and they became arguably the series' most stable couple.
Starbuck, who was engaged to Zak, who died before the series begins, but for much of the series she's romantically linked with his brother Apollo. Although they nearly cheated on Zak soon after meeting, so Apollo may not be the one she's settling for.
On Dr. Quinn, Medicine Woman, the backstory of Loren and Dorothy is revealed to be this—he had courted her back in their younger days before she abruptly married someone else. Her sister consoled him and they ended up marrying.
On My Name Is Earl, Earl helps a Frenchman he once teased by finding a few girls from their class for him to hook up with. One of the girls was nowhere to be found, but "she had a real friendly sister," who ends up having sex with Pierre in the back of Earl's El Camino.
House of Anubis- In season two, Eddie brings this up when he thinks Patricia and Alfie might be into each-other, stating that it might be what Alfie is thinking.
Eddie: "Well, He was into Piper, maybe you're just the next best twin."
In Deadwood, Seth Bullock marries his brother Robert's widow Martha after Robert's untimely death. This is seemingly less about romance and more about acting as a provider for the family and especially a father for Robert and Martha's son William.
Syd Barrett's song "Here I Go" is about a guy who has a crush on a woman who's completely wrong for him, then he meets her sister, finds she's much cooler, and falls in love with her.
"My Darling Clementine"
"How I missed her, how I missed her / How I missed my Clementine / But I kissed her little sister / And forgot my Clementine."
According to Jewish tradition, Laban wanted to create a Double In-Law Marriage between his two daughters and his sister's two sons—Leah would marry Esau and Rachel would marry Jacob. Because Esau was a jerk, to say it politely, Leah prayed to God for help, and He arranged events so that both sisters would marry Jacob instead.
For that matter, the levirate marriage is a similar custom, where a widow marries her deceased husband's brother (or other male relative) if he died childless. However, such a marriage is actually forbidden if the deceased did have children.
Subverted in the Book of Judges: Samson picks a Philistine woman to marry, but after an argument during the wedding feast, her father concludes that Samson doesn't want her anymore and marries her off to one of his companions. When Samson says that he does still want her, the father suggests he marry her younger sister instead. Samson responded by burning downthe Philistines' fields. He had a bit of a temper.
According to A Man for All Seasons, Thomas More preferred out of the two, the sister of the woman he married, but chose her because "it was the right thing to do." He, uh, didn't elaborate.
In Real Life, his motive was that an older sister would, at the time, have found it very humiliating to have a younger sister married first. And they were very happy.
In the Paul Claudel play The Tidings Brought To Mary, Violaine kisses a leper and gives him her engagement ring to sell for money. Her fiancee, upset that she's given away his ring and contracted leprosy, marries her sister instead.
In the DS version of Dragon Quest V, Deboraassumes Crispin has a thing for her, and is just 'settling' for her younger sister Nera. It's obvious to everyone else, however, that he genuinely loves Nera and isn't exactly interested in Debora. Played for Laughs, natch.
In Fire Emblem Seisen no Keifu, Briggid fears that either Jamuka or Midayle will pull this on her since they both had Bodyguard Crushes on her younger twin sister Edain. Her love talks with both males have them saying this isn't the case.
Levin/Fury plays with the trope; Levin had a major crush on Fury's sister Mahnya when he was young, but in a talk event he tells her he's over it and wants to be with Fury now.
In Shogo: Mobile Armor Division, Sanjuro, having thought that his girlfriend Kura died two years before the start of the story, has been going out with her sister Kathryn for six months prior to the start. Kathryn loves her sister and is glad to hear that she's alive, but there is some jealousy between them regarding Sanjuro.
A not-entirely-romantic variation is possible towards the end of Dragon Age: Origins: it is possible to persuade Queen Anora to marry Alistair—the long-lost, illegitimate younger brother of her late husband, King Cailan. Though this marriage is driven by pure pragmatism (Ferelden needs both Anora's firm grip on politics and the Theirin royal bloodline), Anora is shown to have had very tender feelings for Cailan and is slightly confused by the prospect of developing them for his brother.
In General Protection Fault, Maddie is in love with Fooker, but he refuses to choose her over his girlfriend, Sharon, despite having been separated from her by his UGA deployment, and Maddie insisting that he give up on her. Maddie gets together with Fooker's brother, though.
Additional weirdness points for the brothers being near-identical in the looks department (besides grooming), and actually sharing a codename; some people aren't aware of the switch.
In Suburban Jungle, Dover Cheetah eventually switches his affections from main character and unrequited crush Tiffany Tiger to her (half) sister Comfort. As Comfort likes him and Tiffany thinks of him as a friend, this works out well and they beat Tiffany and her beau to the altar by several years.
Hey Arnold! combines this trope with Runaway Groom in the episode "Ghost Bride". It does not end well for the groom and the sister.
Subverted on The Legend of Korra:Korra has a thing for Mako, who likes her too but is dating Asami. After she has a fight with Mako, his brother Bolin (unaware of all the other drama) asks her out, and she reluctantly agrees, apparently hoping it will help her move on. The two have a great time, but the next day Korra has another fight with Mako, impulsively kisses him, only for Bolin to walk in and have his heart broken. He has majorly gotten over it by the time the first season's over, however.
When Eric Clapton fell for Pattie Boyd and couldn't have her because she was married to his fellow musician George Harrison, he briefly shacked up with Pattie's sister, Paula. Paula ditched him, however, upon realizing that she was just a Pattie substitute.
Antonín Dvořák initially fell in love with Josefína Čermáková, though she did not love him back and ultimately married another man. Dvořák ended up marrying Josefína's younger sister, Anna.
As pointed out in the page quote, Mozart did this. When Aloysia Weber turned him down, he married her sister Constanze. They remained married until his death and seem to have done well together.
Henry VIII's first wife, Catherine of Aragon, was originally married to his older brother, Arthur. Naturally it was an Arranged Marriage, so when Arthur died young it was agreed that Henry would marry his brother's widow (because you don't give up a strategic marriage to a literal Spanish Princess whose nephew is due to become ruler of one of the greatest empires the world had yet seen,note The nephew in question being Charles V, Holy Roman Emperor, who was also Carlos I, King of Spain. In the former capacity, he ruled Austria, Burgundy, and the Low Countries as well as (at least theoretically) all of Germany and half of Italy, while in the latter capacity, he held not only Spain but also most of the Americas—and all of their silver. especially not when she and the new king actually know and rather like each other and seem quite compatible personally). This was somewhat problematic—the concept of affinity meant that the couple was technically considered incestuous, so the pope had to give special dispensation to allow it. When five of the couple's six children later died young (leaving only a daughter) Henry claimed that God disapproved of the marriage and that it should thus be annulled, "justifying" the separation of the English Church from the Roman when the Pope refused to retract the dispensation. This led, eventually, to the end of the Tudor succession/the passage of the English crown to the Stuarts, the English Civil War, and the birth of modern liberal representative democracy. Small trope, big impact.
Queen Mary, the paternal grandmother of Britain's Queen Elizabeth II, was born Princess Mary of Teck and was engaged to her second cousin once removed, Prince Albert Victor, the son of the Prince of Wales. Six weeks after the betrothal was announced, he died unexpectedly of pneumonia. She and his brother George, now the next in line for the throne (later King George V), began writing letter to console one another, and the following year she became engaged to him instead. It turned out to be an actual love match.
The fact that they were better match personality wise helped a lot, Queen Mary was having doubts before his death and asked her mother if she could make the marriage a success.
Princess Dagmar of Denmark was betrothed to Tsarevich Nicholas Alexandrovich of Russia, when he died of meningitis, expressing as a Last Request that she marry his younger brother Alexander, which in due course she did.
According to his biographer and son-in-law William Roper St. Thomas More actually preferred the younger sister of his first wife but proposed to the elder because it would have humiliated her to see her little sister married first. Other biographers have suggested that Roper mistook a family joke for fact. Will had no sense of humor and More had a very good one.