Kyo: Because you threatened me!
A common staple of stories featuring Childhood Friends is the Childhood Marriage Promise. Years ago, when two of the main characters were small children, they promised to marry each other when they grew up. Now they're in High School or university, and She Is All Grown Up. Sometimes, the couple fall in love for real and they finally fulfill that promise. Other times, one of them is the Unlucky Childhood Friend whose heart gets broken.
A slight variation, one that usually comes up in Fantasy or Sci-Fi anime, is where the boy promises to always protect the girl (which, in the traditional sense of marriage, is pretty much the same thing). See Bodyguard Crush. See also Declaration of Protection, which can be read both ways. Often arises in a Forgotten First Meeting scenario.
Compare Puppy Love, which may lead to this. When it's the parents who make such an agreement, you have the decidedly-less-heartwarming Arranged Marriage. When two adults make such a deferred arrangement in order to avoid being single in old age, it's a Fallback Marriage Pact.
- A candy commercial featured a little boy asking a little girl to marry him, and giving her a Life Saver as an engagement ring.
- Ai Yori Aoshi uses it as its central theme, as Aoi and Kaoru were promised to marry due to their families... but the promise was broken due to Kaoru walking out on his horribly abusive grandfather. However, when he meets a grown-up Aoi who still likes him, Kaoru falls for her all over again.
- Boku Wa Imouto Ni Koi O Suru features a marriage promise between Yori and Iku. Despite the fact that they're twins they later decide to make good on the promise.
- The cousins Li Shaoran and Li Meiling in the anime version of Cardcaptor Sakura. They don't go through it, since the promise was that Meiling would be Shaoran's bride until he found someone he loved more... thus Meiling steps aside willingly when she realizes that he's fallen in love with their common friend Sakura. The scene where Meiling breaks down crying on the lap of Sakura's own Unlucky Childhood Friend, Tomoyo, is heartbreaking.
- In Code Geass, Nunnally and Euphemia have a good old laugh when they remember the times they fought as children over who would get to marry Lelouch. Considering they are, respectively, his sister and his half-sister, and further considering he has a metric ton of Incest Subtext with Nunnally (lampshaded more than once) and actually calls Euphemia his 'first love', it's probably for the best that they never mention this conversation to him.
- In DARLING in the FRANXX, Hiro made such a promise with Zero Two in a flashback in Episode 13, and states that if they marry, he'll become her darling. That promise becomes the main reason why Zero Two is so hellbent on becoming human.
- In Detective Conan, it seems that a very young Heiji Hattori made one of these. Thing is, it looks like he made it with Momiji, NOT with Kazuha. In the end, it was a mix of The Promise and Accidental Marriage: he promised her something else and she believed it was a future marriage vow. She doesn't take it well, of course.
- In Dragon Ball, Chi-Chi and Goku first meet as children, and Goku promises to marry her, thinking marriage is a kind of food. He says so when an angry and all grown-up Chi-Chi brings it up in the Tenkaichi Budokai; Chi-Chi is saddened upon realising that she had been sort-of waiting in vain... but Goku then adds that he doesn't want her to be sad and that he takes his promises seriously, so he officially asks her to marry him right there.
- In a bit of a twist, in The Five Star Stories, Lachesis promises to marry Ladios/Amaterasu when she's 10 or so... and he's over 100. But then, he's a god, she's an Artificial Human (and possibly an incarnation of a goddess) & they're both immortal, so it's not nearly as Squicky as it sounds.
- Fruits Basket:
- Kyo's promise to Kagura was extracted by her threatening him with a knife (or a large rock in the anime). By the time of the story, he's interested in someone else.
- A variant happens between Kyo and Tohru, though he makes the promise through Tohru's mother Kyoko, whom he had an Inter Generational Friendship deal with. When Tohru gets lost on her way home from school, Kyo makes "a man's promise" to find Kyoko's daughter and protect her. When Tohru is brought home by someone else, Kyoko teasingly tells him that she'll put the promise "on his tab". At the end of the series, when Kyo and Tohru are in their late teens, they agree to basically go live together after graduation (and eventually do get married); Kyo thinks back to his promise, and relates his vow to protect Tohru to him essentially being her husband - that he will keep his promise for the rest of his life.
- Played with in Fullmetal Alchemist, when Alphonse asks Edward if he remembers the time when they fought over who would marry Winry. Al won the fight but she rejected both of them saying "I don't like guys who are shorter than me". Incidentally, by the end of the series Ed is now (slightly) taller than Winry.
- Full Metal Panic? Fumoffu. A Lonely Rich Kid, in his attempt to woo Chidori, tells her about a recent tragedy that has shattered his spirit. His tale begins as a clichéd romance thwarted by a terrible car accident. Then it turns out that the 'tragedy' is that the girl in question eloped with a boy she met in the accident, and moved to Amsterdam. He still gets postcards.
- Played with in Futakoi: the Ichijou twin sisters (together) expressed their intent to marry Nozomu when they all will grow up. When they did grew up and met again, there were definite affections from all three sides, all right. Each (separately) reminded him about this proposal and tried to downplay her own role (claiming it was half- friendly competition, half- cooperation with other sister)... only to set her sibling forward, while both still paid more attention to their "non-fiance" than to everyone else. It's Futakoi, though, so a Mind Screw was really to be expected.
- Implied, but not directly said in GaoGaiGar, when Hana reminds Mamoru about a promise they made when they were young (er) children. Mamoru can only blush in response. Of course, they're all but dating as it is.
- A bonus story in ½ Prince shows that Zhou/Wicked fell in love with Lan when she (then twelve) asked her to marry him.
- Hayate and Athena from Hayate the Combat Butler. They promised to spend the rest of their lives together and even gave each other promise rings. Izumi promised to be his bride as well.
- Happens between Tagaki and Rei as a pinky swear in High School Of The Dead .
- In Honey Crush, Kyouko and Madoka shared one when they were younger. They're both female but Madoka thought that Kyouko was a boy at the time.
- In the anime version of Inuyasha, Koga lightheartedly promises to marry wolf-girl (and granddaughter of a very powerful wolf youkai whom he quite respects) Ayame, then still a young child, after he saves her from being killed. She reappears all grown-up and demands he fulfill his promise, but he's already in a Love Triangle with Kagome and Inu Yasha. Even worse, the poor guy doesn't remember a thing about it, and Ayame not only is hurt and angry as Hell with quite the reason, but Kagome is pissed at him too because she supports Ayame's bid for Koga's affections. (Though it's hinted that Koga fakes not remembering, since he doesn't want Ayame to become Naraku's target) By the end of the series, Koga finally fulfills his promise to Ayame, and they're Happily Married.
- Hazumu and Tomari in Kashimashi: Girl Meets Girl, with the added complication that Hazumu is now a girl. Amusingly, the original promise was Hazumu promising to be Tomari's bride, which received an angry response from Tomari that as a boy, he'd have to be the groom. Oh, how things can change...
- Sanpeita, the protagonist of Kemeko Deluxe! made one ten years ago with a girl he knew. Ten years later, a girl who looks strangely like her in some sort of Powered Armor returns to protect him...and also claims to be his wife.
- Infinite Stratos had Ichika promise that when she was a better cook, he would eat Rin's sweet-and-sour pork every day. Unfortunately for her, he took that promise in a literal sense.
- A somewhat similar to Inuyasha case shows up in Kenichi: The Mightiest Disciple. Years ago a drunk Sakaki jokingly agreed to marry the young daughter of a friend if she got him more booze. But now Jenny Grey wants to hold him to that promise.
- Chihiro and Ritsuko in Kujibiki Unbalance. Of course, considering the source, it's an Affectionate Parody.
- The promise is made between Ryouta and Chika when they are children in Kyou no Go no Ni. A bit unique in that they're still kids by the time of the anime, just slightly older, and it's actually the male half of the pair who remembers it.
- The Laughing Target has a Childhood Marriage Promise that jump starts the plot. One partner's determination to uphold the promise is shown to be creepy and unhealthy and that's on top of her being a Yandere with supernatural powers. It's not cute and romantic.
- The whole point Milk is obsessed with—and creepily stalking—Reiner in The Legend of the Legendary Heroes.
- Love Hina:
- Keitaro is determined to find the girl he pledged to marry as a child, although he can't for his life remember who she is. (All evidence points to either Naru or Mutsumi — or both. Mutsumi claims it was Naru.)
- The end of the manga reveals that as a child, he wanted to marry Mutsumi at first, but she made him promise Naru that he'd marry her — because Mutsumi knew Naru was also in love with him, and she wanted them both to be happy. Since the entire manga plays on Urashima Taro, it was ultimately Mutsumi, the fated girl, who said "Screw Destiny" and gave away the guy as far back as when they were preschoolers, and the whole manga is just the fallout of that choice. Given that his aunt beats him to "Toudai", Screw Destiny is very much in play throughout the manga.
- This is also played with at the end of the manga when he asks his grandmother who his promise was with and she yells out (while boarding a helicopter) that the girl he promised has been with him 'all along' prompting EVERY GIRL AT HINATA SOU to proclaim that she's the one!
- In Maison Ikkoku, Yusaku Godai made such a promise with his cousin Akira, who in the present day is taking care of Yusaku while he's in the hospital with a broken leg. He's worried that she remembers the promise and will try to keep it, but actually she's secretly engaged to another guy who she's planning to elope with.
- Maken-ki!: The promise between Takeru and Inaho plays out differently, depending on whether you're reading the manga, or watching the anime:
- Inaho initially claimed to be Takeru's fiancee, which he had no recollection of. It doesn't get sorted out until chapter 59, where Takeru finally remembered having promised to always be together with her. But Inaho said she should be the one to apologize since, she never actually said she'd marry him. It was simply an idea she latched onto as she grew older.
- The anime differs by explicitly having Inaho promise to marry Takeru, during a flashback in episode 3. During which, Takeru swore he'd become strong enough to protect Inaho forever. Unlike the manga, he never recovered his memory of it and it was never brought up again. So it was simply left hanging.
- According to some side materials, a very young Dorothy Catalonia from Mobile Suit Gundam Wing made one with her distant cousin and her father's favorite pupil, Treize Krushrenada. We don't know if Dorothy actually wanted Treize to fulfill it, though she did show affection for him. And considering that he died at the end of the series...
- Prince Jeord set up an arranged marriage between himself and Katarina when they were 8 in My Next Life as a Villainess: All Routes Lead to Doom! after she got a scar on her forehead while with him (as such a deformity could seriously hurt her chances of finding a husband otherwise). Within the original game timeline, he only did so in order to deter other potential suitors and hates Katarina due to her being a clingly Spoiled Brat. Within the altered timeline where Katarina has the Past-Life Memories of a Japanese schoolgirl, the situation is reversed; she's the one who wants out of the engagement due to thinking that he's a cold manipulator like his game counterpart, while he is hopelessly in love with her due to her kind and quirky nature.
- In Nisekoi, the main character Raku Ichijou wears a pendant with a lock from the time he was 5 years old. He spent summer playing with his first love and when they had to say goodbye, they promised to each other that when they meet again when they're grown up, they will open the pendant using her key and get married. Things get complicated because three different girls with keys appear and they all have a vague memory of knowing Raku when they were little and making some sort of promise with him, but Raku is sure he made the promise to only one girl. After many turns around the issue, the whole thing is made clear: Chitoge was the one who came up with the idea of the pendant and the keys from a children's book she liked and she wanted to make the marriage promise with Raku. However, after finding out Raku and their friend Kosaki liked each other, she decided to back out and let them make the promise together instead. However, when all three finally remember what's going on, Raku has moved on from liking Onodera and decides the promise isn't what's most important anymore.
- Yuuto of Omamori Himari had made the Declaration of Protection (or more accurately, I Will Definitely Watch Your Back, as they were planning to be demon hunters, and her spells only go forward) version to Kuesu in his youth while their families worked out a betrothal between them. Then they separate for about a decade. When they next meet, he had completely forgotten her, completely rethought his views on demon hunting, and acquired an Unwanted Harem, most of whom are members of the demon races that they had originally planned to exterminate in their youth (And which Kuesu still wanted to do). It makes for a rather bumpy reunion.
- Eita and Ai do this in Oreshura. While he totally forgot about it, she remembered it very well, and even shows him the "marriage certificate" they made as kids. Hilarity Ensues as he runs from her while she tries to get him to stamp the certificate.
- In Otaku no Musume-san, Nozomi and Niichi made one as children in the same orphanage. It fell apart and the fallout drives much of the plot.
- Pokémon: James made one with Jessiebelle but he didn't know her real personality and once she showed her colors, he didn't want anything to do with her. He ended up running away as a child in order to avoid marrying her, and didn't return home until his adulthood.
- It eventually turns out that Ranma and Ukyo in Ranma ½ have one of these, made when Ukyo tried to make some of her family's okonomiyaki sauce while they were kids. She promised to let Ranma taste it when it finished aging after ten years, if Ranma would vow to "look after her for the rest of her life" if it turned out good. Of course, at the time, Ranma didn't know either that Ukyo was actually a girl or what he was promising, and through a lot of confusion the promise ends up being broken when it comes up again. Unfortunately for Ranma, Genma and Ukyo's father had brokered an Arranged Marriage shortly after he and Ukyo made their Childhood Marriage Promise (which Genma tried to run out on), meaning Ukyo still persists that she has a claim to his hand. Because she does. This is further complicated by the fact that Genma has promised Ranma's hand in marriage to several girls (and in the anime to a couple others as well) because he's a jerk.
- The events of the first Urusei Yatsura movie, Only You, were set in motion when as a child Ataru played a game of shadow tag with a girl who turned out to be an alien; it is a custom on her planet that stepping on someone's shadow counts as a marriage proposal. 11 years later she turns up with an interstellar battleship to claim her husband...
- In World Conquest Zvezda Plot, it's revealed in a flashback that Jimon Asuta proposed marriage to Shirasagi Miki when they were both children. She turned him down, and only brings it up in the present to embarrass him.
- Referenced in Yu Yu Hakusho. When Yusuke proposes to Keiko, she looks stunned... until her dad starts laughing and reminiscing about how Yusuke always tried to make up with her after a fight by asking her to marry him.
- Vampire Knight: Slightly averted with Yuuki and Kaname, where their lineage expects a Kuran born son and daughter to marry each other upon reaching adult age, as is custom to most pureblood lineages.
- Tales of Wedding Rings: Shortly after they met, Hime told Sato that the rings she wears around her neck are her wedding rings, and asks him to marry her one day. Once they grew up, he assumed she forgot about this, until he follows her through a portal to another world and finds her about to get married to some guy she's never met. She immediately puts the ring on Sato's finger and kisses him, magically sealing their marriage and making him the Ring King who must fight the Abyssal Lord.
- Countess Gwendoline and Roderick in the Douwe Dabbert story Florin the Loafer. Very inconvenient for the villain who wants to marry Gwendoline to become a count.
- The plot of the comics in the Daily Planners line Artilugia is based around the tween heroine Aldonza creating the titular Sexier Alter Ego Artilugia as a way to secure her marriage promise with her beloved Bruno, whom she believes is being seduced by the Alpha Bitch of their classroom. The resultant situations becomes an Imaginary Love Triangle when seen from her perspective, and a Two-Person Love Triangle if seen from Bruno's.
- In Calvin and Hobbes, Calvin offers twice to Susie to not date her. The first time, he's insulted that she signs so quick, the second she pummels him for suggesting it will take her eleven years to find a prom date.
- In DC Nation, the "42 Days" Flashback. Forty-two days into sobriety, homeless, and with nowhere else to go, Roy shows up on Donna's doorstep.
Donna: "I swear upon the Styx that I will never look upon you with hate. Nor will I leave your side if you feel in your heart I belong there."
- At the time, neither one really understood the implications of that vow. Between the Titans of Myth and Dark Angel, the two parted. Roy ended up the Unlucky Childhood Friend when Terry Long came into the picture, and had a wonderful train-wreck of a relationship with Cheshire. Almost twenty years, an acrimonious divorce (hers), a couple of murder attempts by his ex, a naked trip into hell, a couple fights with angel Dark Angel, and a return from the dead for both later...They finally get there.
- Happens a lot in Doctor Who fanfic, between Kid!Doctor and Kid!Master. This also shows up in stories that show Amy and Rory as children.
- In the Rise of the Guardians and Megamind crossover fic Protectors, we get a very heartwarming example when the group of children, including Kid!Roxanne, defend Kid!Megamind (known as Teal here) from two Manipulative Bastards.
Roxanne: Teal is my very best friend in the world, and one day, I'm gonna marry him!
- In Unremarkable, Peter Parker decided at the age of six that he was going to work at Oscorp and marry his best friend, Harry Osborn. When Harry brings it up in the present, Peter is 80% sure he's joking.
Peter: Harr, when we were six, I also decided that we were going to get married one day. Decisions at that age don't count.Harry: Yes, well, I understand that an SI wage doesnt really pay enough for you to afford a ring yet, but Im not looking to get married until Im at least 25, so I can wait.
- In the Harvest Moon 64 fanfic Wine Red no Kokoro, Karen and Jack met at age five while Jack was vacationing at his grandfather's farm. When Jack left Flowerbud to go back home he promised that he'd marry Karen when he grew up. Jack remembers Karen and comes back years later, but Karen has trouble remembering her childhood friend's face and doesn't recognize Jack at first.
- Brother Bear 2 is based on an accidental version—as children, Kenai gave a necklace to his friend, Nita, and the two swore to be best friends forever, despite living in different villages. Apparently the spirits considered them betrothed now, because years later they interrupt Nita's wedding, and won't allow the new marriage unless she tracks down Kenai and performs a ritual to annul the agreement. You'd think Kenai choosing to live the rest of his life as a bear would have done that already, but no.
- Mary Hatch promised George Bailey that she would "love him til the day she died" in It's a Wonderful Life, although she whispered it into his deaf ear so that he couldn't hear her.
- In Fiddler on the Roof, Motel tells Tevye that he and Tzeitel, as children, "gave each other a pledge" that they would marry each other. (They still want to marry, but tradition requires that Tevye, as Tzeitel's father, approve the marriage; his mention of the pledge is part of his attempt to convince Tevye to give his permission.)
- A young Forrest Gump and Jenny fall in love as children, in the shadow of, if not The World Tree per se, then at least a very very large tree.
- Sweet Home Alabama starts with a memory/dream sequence of the main character and her childhood friend promising to marry each other. The backstory shows that it didn't end happily. They did get married, but soon found it wasn't as glamorous as they thought it would be. After a miscarriage, Melanie leaves for New York, where she spends the next seven or so years building a fashion business. It's when she wants to marry again she runs into problems...she and her childhood romance never divorced; he refused to sign the papers. After a return to her roots and an analysis of just why their marriage failed he signs the divorce papers, only to find at her wedding that she hadn't signed them. She realizes she's still in love with him, not her new fiance. They decide not to get divorced, after all.
- In Mongol, Temudgin, otherwise known as Genghis Khan, picks out his arranged bride, Borte, when he's little. Guess who is his Love Interest and who he obsesses over for the rest of the movie?
- In East of Eden, Aron promises to marry Abra under a willow tree, and they even act like they are married, but then Aron goes off to war and gets killed. Abra ends up with Cal, Aron's brother, who she had grown to love while Aron was at college.
- In Star Wars, Anakin tells Padme that he's going to marry her someday. Considering his abilities as a seer, this could be a childhood marriage promise (possibly foreshadowing Anakin's arrogant and demanding nature) or stating what he sees as fact.
- Twelve-year-olds Sam and Suzy get unofficially married in Moonrise Kingdom.
- In The Wolverine, Mariko jokes that she was going to marry Harada, but couldn't because they weren't fifteen.
- Invoked in Teresa Edgerton's The Castle of the Silver Wheel, in which Prince Tryffin pulls a Speak Now or Forever Hold Your Peace in the nick of time to prevent Gwenlliant from being forced into an Arranged Marriage with a notoriously abusive man. When asked if they have a Childhood Marriage Promise (which would constitute a pre-contract, thus acting as an impediment), Gwenlliant claims that they do — because Tryffin Cannot Tell a Lie, so she has to do it.
- Scout and Dill in To Kill a Mockingbird. Scout was based on the author, Harper Lee, while Dill was based on her childhood friend, Truman Capote, author of Breakfast at Tiffany's and In Cold Blood. Incidentally, Capote was gay, and Lee never married.
- In Naomi Novik's Temeraire series, Laurence and a girl he knew made a half-serious marriage proposal when he was thirteen and she was nine, just before he went off to join the Navy. Given that this occurred in early nineteenth century Britain and both parties are from minor nobility, their families regarded this as something of an actual engagement. When he became an aviator at thirty, his prospects and suitability greatly reduced by it, they had to call it off.
- Nikolai and Sonya in War and Peace.
- 10-year-old Tommy Bangs and Annie "Nan" Harding plan to get married in Little Men; ten years later in Jo's Boys, Nan can't believe Tom still expects her to go through with it. They don't; she remains unmarried but happy as a Hot Librarian, and Tommy marries his other suitor Dora.
- The book Quest for a Maid has a scene where the 10-year-old heroine Meg rescued a 6-year-old boy, Davy, from some bullies. Davy was so grateful he asked her to marry him on the spot, and she accepted. His father overheard, and while acknowledging it was just kids playing, decided this was perfectly suitable, talked to Meg's father, and made it an Arranged Marriage. Davy became the Unlucky Childhood Friend later, though, when Meg reached the age when she was ready to marry but realized that Davy was still too young,and she didn't want to wait.
- In Hetty Feather by Jacqueline Wilson, Hetty's older foster brother Jem promises to marry her when they are grown up so that she can rejoin the family after being sent back to the Foundling Hospital. A modern-day version happens in Kiss, where Sylvie and Carl had such a promise as children, but Carl comes out as gay.
- In Morris Gleitzman's Bumface, the two main characters actually get married as children, in order to circumvent an Arranged Marriage.
- In The Exiles series by Hilary McKay, 10-years old Rachel is so enthralled by the nice, polite and charming French exchange student Philippe that she announces she's going to marry him when they're older. When her sisters scold her for harassing Philippe, she just smiles and says that he hasn't said that he doesn't want to. She gets him in the end.
- In Bloody Jack, Jacky and Jaimy promised to get married someday back when they were children on the Dolphin. They still intend to go through with it, despite being totally unsuited for each other.
- Rand al'Thor and Egwene al'Vere of The Wheel of Time were all-but promised to each other. They each muse on it in their internal monologues as one of the more amusingly nostalgic parts of the world they'd left behind once they'd assumed the mantles of Dragon Reborn and Amyrlin Seat, respectively.
- In the novel Zinnia, Zinnia and Tate do this. They fully intend to go through with it, having been close friends for years, but a black woman and a white man in 1922 get hatred from all sides. They try to date other people. It only works for one of them. Who that is goes back and forth a few times before a complicated Bittersweet Ending.
- The Adventures of Tom Sawyer: Tom Sawyer and Becky Thatcher, somewhat complicated by the fact that she's not the first girl he was ever engaged to. And that Becky gets PISSED when she finds out.
- In the Halo: Evolutions story Palace Hotel, it is revealed that John-117 (Halo's Master Chief) had a childhood friend named Parisa. The two became friends after John saved her from drowning in a lake, and later John promised to marry her and keep her safe. He was never able to keep it, however, as he was abducted two weeks later for the SPARTAN-II Program and replaced with a flash clone which died not long after. Due to this, Parisa believed that John had died, though she kept with her a picture of herself and John taken by their parents. Years later, John would meet her again during the Battle of New Mombasa. At the time, Parisa was holding the picture of herself and John as children as seen here◊. Just as John was intending to remind Parisa to not bring personal items to a combat zone, he recognized the picture. Parisa, obviously not recognizing John because of his armor, explained the story behind the picture to him and said that although it was silly and John was "dead", she intended to hold him to that promise. Despite the sudden flood of memories, John couldn't bring himself to reveal who he was, knowing that doing so would be a massive security breach. Instead he maintained his stoic facade and the two of them began planning a counterattack against the Covenant.
- Inverted in the Anne of Green Gables series. As children, Rilla Blythe and Carl Meredith make a promise never to marry each other as they are genuinely just close friends and are sick of being teased about being "married" at school.
- In the episode Jack in the Box of Jonathan Creek, the character of Jack Holiday proposed to his child co-star (implied to be as a joke), but then on returning after ten years, met her again as an adult and married her. He then hires a man to kill her.
- Turns out to be the whole cause of the plot of Harper's Island, after nine-year-old Abby told eleven-year-old Henry that she wanted to live alone with him forever on the titular island. Sixteen years later he tries to hold her to this - by luring her to the island on false pretenses, murdering all third parties and faking their deaths. She doesn't see the romantic side. To say nothing of the fact that he later found out they were half-siblings and didn't let that affect his feelings.
- In Toshiie to Matsu, Matsu and Toshiie promise themselves to each other when Matsu is quite young (one source says she was only 11-ish at the time).
- The live-action segment of one episode of The Super Mario Bros Super Show! plays with this: Mario receives a letter from one "Roxanne", reminding him of "his promise" made 15 years prior. Mario and Luigi are both assuming it's along the lines of this trope, but at the end it's revealed that Roxanne is already married with five kids; Mario's promise was instead to sell her plumbing supplies at wholesale price.
- A childhood friend of Mary Jo's turns up in one episode of Designing Women to remind her of their CMP. She seriously considers it.
- Miranda Lambert's song "Me and Charlie Talking":
Charlie said he wanted to get marriedBut we were only ten so we had to wait...
- The trope is Referenced and subsequently Played for Drama in "Smoke And Mirrors" by Jayn. It's about a yandere Villain Protagonist getting angry that her childhood friend broke the promise. She decides to take his wife hostage and threatens to kill her if they don't divorce, and follows through when she finds out they've already started a family together.
You said you'd always be my friendThat we'd get married when we both got olderI've never heard those words before.You made me long for something more, but then she tried to steal your love.
- Older Than Television: Gilbert and Sullivan operettas used this trope repeatedly.
Ida was a twelve-month old,
- The Grand Duke (1896) has plot involving dueling to the technical death by cutting a deck of cards is a bit Yu-Gi-Oh! to make the subject of a proto-musical. Suffice to say that Ludwig is saddled with all the commitments of the people he beats at cards, and they turn out to involve a lot of romantic ones. Once he's been forced to marry his third wife... well, it seems like he should have skipped that third one, when the woman the Grand Duke was engaged to in infancy shows up.
- This trope's central to the plot of The Gondoliers
- Princess Ida devotes an entire song, "Ida Was a Twelve-month Old," to this:
Twenty years ago!
I was twice that age, I'm told,
Twenty years ago!
Husband twice as old as wife,
Augurs ill for married life;
Baleful prophecies were rife,
Twenty years ago!
- The Nerd teases this when Rick spins a story about proposing marriage to an 8 year-old-girl with a necklace and her mother being so mad, leading to him being told it's a very sweet story... and then he reveals he was 30 when he did it.
- In Aggressors Of Dark Kombat, Kisarah Westfield's reason to enter the ADK tournament is that she wants Joe Kusanagi to acknowledge the one they made as children. She succeeds, but only in her own ending. And in NeoGeo Battle Coliseum.
- In Castlevania 64, in Carrie's bad ending, Malus gets Carrie to make a promise to marry him when the two are old enough... and then ominously says, "Now we have a binding contract..." For those not in the know, Malus is Dracula: essentially, the promise is the cornerstone of Unholy Matrimony and poor Carrie hasn't the faintest idea.
- Happens in some Fire Emblem supports:
Franz:I don't know what it is you plan to do with your life, but as long as we travel the same path, would you let me walk beside you?......Amelia: ...let me be your shield to protect you...Franz: And I will be your sword and fight for you. From now on.
- Blazing Sword has Priscilla and Raven, which looks kinda cute until the player realizes that they're siblings. Priscilla perfectly knows that it's not a binding promise at all and that Raven would never marry her, but since they have been apart for many years, she yearns for him to stay by her side now that they've been reunited.
- The teenaged Amelia can give similar promises to either of her similarly-aged prospect boyfriends, in their A Supports: she can promise Ross to help him Doomed Hometown, tell Ewan that they'll go Walking the Earth together, and give Franz a Declaration of Protection that he reciprocates:
- In Fire Emblem Fates, Female Kana (anywhere around 10 to 13) and Kiragi (probably just a little older) can make one if they reach a S support.
- In Harvest Moon: Back to Nature, the goal of the game is to revive your dead grandfather's old farm that you spent a summer at as a child. While there, you met a girl who you promised to come back for and marry. The girl always turns out to be the bachelorette you marry.
- A side quest in Jade Empire involves sorting out one of these, with the twist that the Unlucky Childhood Friend trying to cash in on the promise has grown up to be the leader of a gang. Fortunately, you can not only convince her to let it go, but you can also find a suitable husband for her. Or, if you're in the right mood, convince her to kill her romantic rival, followed by accidentally killing the one who made the promise. And then she realizes what she's done, breaks down and attacks you, resulting in you killing her and her entire gang.
- The Legend of Zelda:
- Link has found himself engaged in this way to the Zora Princess Ruto (who does grow up to be rather easy on the eyes) in The Legend of Zelda: Ocarina of Time and the Maku Tree in Oracle of Ages, even though he never really agreed in either case.
- Also in Ocarina of Time, Talon brings up the idea of engaging Link to his daughter Malon. Link can actually say yes, but either way Talon claims to be just kidding.
- In Majora's Mask, Kafei and Anju had one of these, promising each other to exchange wedding masks on the day of the Carnival of Time which according to Termina tradition was the best day for couples to be married. The promise proves so meaningful that Kafei refuses to reunite with Anju without retrieving his wedding mask (the Sun's Mask) from Sakon, who stole it shortly before the events of the game began.
- Magical Diary: Neither party has any interest in going through with the promise... except that the choice may not be up to them.
- In Persona 3 one of the Social Links ending involves a little girl (Maiko) who promises to marry the High School protagonist when the time comes. In FES the protagonist may later on be met by her father, who heard of this from a letter from his daughter and accuses you of trying to pull Wife Husbandry. Not that it matters because you die within the next two days.
- If the player maxes out his cousin Nanako Doujima's Social Link, at the end of Persona 4, on the last day before you leave the town Nanako will promise to marry you when she grows up. Her father Ryotaro for the most part laughs it off as something she's just saying because she'll miss you, but he makes it clear that she is off-limits no matter what age any of you are. However, if you maxed out Doujima's Social Link as well... well, he's going to hold you to that.
- In Rune Factory 2, the second game in a spin off series of Harvest Moon, in the second half of the game in which you play as your child, you propose and "marry" your boyfriend/girlfriend (s in the case of Serena and her twin, Sera). Though, it's just a promise that you will marry them in the future. Except in Serena and Sera's case when you play as your daughter. You are stopped due to the priest saying how "girls can't get married to each other"(and how the twins just think marriage is one big tea party in the English version).
- Rune Factory Oceans also features one between Aden and Sonja, but it's never brought up unless the former proposes to the latter.
- In Tales of the Abyss, Luke and his cousin Natalia made a mutual Childhood Marriage Promise at a young age. Shortly after, he was kidnapped and lost all his memories, forgetting all about it... In reality, the "Luke" that returned was not the true one but a clone, who is the Luke that the audience meets. The real Luke, now named Asch the Bloody, still cares for Natalia... who isn't his blood cousin, technically speaking. And then Natalia starts to differentiate between the two and implies she might have feelings for both. Which one she picks at the end, not the least due to the Heroic Sacrifice of both Asch and Luke and the Gainax Ending obscuring who came back to life in the post credits scene, is unknown. It doesn't help that Natalia has Luke recite the promise before the Disc-One Final Dungeon, and his actual age could have that count.
- In Tomodachi Life, kid Miis can't get married, but they still can fall in love. Instead of proposing marriage to their sweetheart like adults do, kid Miis instead promise to get married when they become grown-ups (a process you can accelerate by spraying them with Age-o-Matic Spray).
- One sidequest in Yo-Kai Watch has you fetching a ring for a little boy who wants to propose to his "girlfriend." The sidequest is even called "Marry Me Someday?"
- In Zone of the Enders: The Fist of Mars, when Cage is reunited with a group of orphans he saved earlier in the games, one of them reiterates the promise to marry him when she grows up. This earns Cage a nasty look from Myona.
- A variant in Umineko: When They Cry: Battler Ushiromiya promised to the maid Shannon that he would "come back to take her away on a white horse". She remembered it and waited desperately. He didn't return to the island for six years and completely forgot about it; not only did he have a falling out with his father for marrying too soon after his mother's death and decided to leave the family, but he also didn't take his own promise to Shannon as seriously as she did. It snowballed into a horrible tragedy for the Ushiromiya family.
- In True Love Junai Monogatari, there was one between the main character and the local Tsundere and Patient Childhood Love Interest, Mikae Morikawa. The Player Character, as a little boy, repeteadly swore that he'd make Mikae his bride; as they grow up, he never really forgets it... and if he pursues Mikae, he's surprised to learn that she not only remembers it, but deep down she has always been hoping he would bring it up and ask her to fill it wit him.
- Makoto proposed to Inori when they were little kids in Shiny Days. For him, it was some sort of weird power grab. If he combines his father's hospital with her family's status in town, together they could rule the world.
- Haru proposed this to the protagonist Kyousuke when they met as children in The Devil on G-String. Though they were not married by the end of the game, Haru giving birth to Kyousuke's daughter pretty much unofficially set their relationship & marriage in stone
- In Amnesia: Memories, it's revealed on Shin's route that the heroine tried to make a childhood marriage promise to Toma but Shin took advantage of Toma's moment of hesitation to accept the promise instead. And Toma still hasn't gotten over Shin beating him out for the heroine's affections over a decade later...
- Virginia and Jacob in Magical Diary made one as children, complete with a marriage contract written in crayon. If the player pursues Virginia, then her brother Donald will dig up the contract on Valentine's Day and send it to her as a joke. The problem is that in this universe, the sworn promise of a witch or wizard is magically binding, and someone who breaks a promise will permanently lose their magical powers. So because of this promise, Virginia and Jacob actually have to get married once they turn eighteen. Virginia is not happy about this, but if the player makes the right choices, they can offer to marry Virginia instead.
- A variation can occur in Long Live the Queen if Elodie chooses to move Adair to the castle and marry him after his father passes away. It's more politically charged than the usual examples, since it's an Arranged Marriage and Elodie sets it up without input from Adair, but they're close in age and wait until they're older to marry.
- In Muv-Luv Extra, Takeru made one with Meiya, but has since forgotten about it.
- Meat Shield: Not so much a promise as a crazy girl convincing herself (and a chunk of the town) that Dhur was going to marry her.
- Axis Powers Hetalia:
- Holy Roman Empire to North Italy. Which, if the "Germany is HRE" theory is correct, makes Germany's awkward proposal in the Valentine's Day strip means it gets fulfilled.
- Another one for North Italy, though this one is a bit weird. When N. Italy and Romano were little kids Spain was an adult already. Spain said he would marry N.Italy when N.Italy grew up (and gay marriage was legal), then Romano got upset wondering what would happen to him if they got married. Spain than says he'll marry both of them. Centuries later, Gay marriage is legalized and N. Italy doesn't remember his promise to Spain, so Spain dejectedly tries to ask Romano. Romano doesn't say no, but he doesn't say yes either. And it's never mentioned again.
- Sleepless Domain: Carina and Amahle not only made this promise to each other, they declared themselves already married, much to the confusion of their third grade teacher. They drifted apart, but end up reunited when they discovered they were thematic partners and have been Sickeningly Sweethearts ever since.
- Here's a sweet Real Life example: two German children, 5 and 6, tried to go to take a trip to Africa so they could marry one another. Although they failed to, there must obviously be a promise to try again in the future. The story can be read here.
- The story goes that Wolfgang Amadeus Mozart proposed marriage to Marie Antoinette when both were children (he had just performed for her family). In the event, each married someone else.
- St. Elizabeth of Thuringia, the daughter of King Andrew II of Hungary, was betrothed to the 10-year-old Louis of Thuringia at the age of 4; they were married 4 years later. Their marriage was extremely happy until Louis died on crusade. She left the Thuringian court to escape the family intrigues, died at the age of 24 in (almost surely self-imposed) great poverty, and was canonized 4 years later in 1235.
- Explorer Sir Ranulph Fiennes (a cousin of the actor Ralph Fiennes) met his future wife when she was 9 and he was 12. They remained married for 34 years, only ending with her death from cancer.
- In Denmark, a very young couple, both 18 years old, got married. Turns out that they've known each other since kindergarten and around their early teens started dating each other after remembering that they made a promise.
- After a declaration in 19th-century Russia that Jewish boys as young as three would be taken from their parents, converted to Christianity, and drafted into the army, Jews devised a Loophole Abuse: They would (at least officially) marry their children off, since soldiers had to be bachelors. In some cases, showing the marriage contract to the police worked; in some it didn't.
- Joan of Kent, a cousin of King Edward III, claimed a childhood marriage promise to one Thomas Holland as grounds for the annulment of her marriage to the Earl of Salisbury. Since Joan was a wealthy heiress her husband did not take this well but under Church law of the time Joan and Thomas had rendered any subsequent marriages to other partners illicit with their childhood vow.