When a character is in love with someone he/she hasn't met yet.
The character knows what their beloved looks like, or knows their name, or sometimes both. But for one reason or another, the infatuated one has never seen the person they love in real life. They know that they'll meet someday, Because Destiny Says So, and they'll wait for their beloved to make an appearance.
Traditionally, the beloved was seen in a dream or premonition, was foretold by a fortuneteller, described by a third party, or seen in a portrait, sculpture, or drawing. New technology has added photos, videos, e-mail, phone conversations, chat, or online gaming sessions, and radio, tv, or movies to the possibilities. Rarer methods involve finding an item of clothing, a book, or some other personal possession of the beloved one. May result in Stalker with a Crush.
Can be the result of a Reincarnation Romance. Girl of My Dreams is the subtrope that covers specifically dreaming of the beloved before actually seeing them.
Fushigi Yuugi: Hotohori as a child already wondered if the priestess of Suzaku "could love him one day". He did not change his opinion by meeting her but it's subverted because it is not with him that Miaka is in love.
Mint Na Bokura has Yoshiaki, who fell for Maria after hearing his brother talking about her. When they finally meet, he promptly asks her out.
In Black Jack, the titular doctor performs a retinal transplant on a blind girl, allowing her to see. She starts getting visions of a young man, who she becomes curious about and gradually falls in love with. It nearly goes very badly when it's discovered that the man she's seeing is an imprint of what the previous owner of the retinas saw, and that said previous owner saw him because he'd murdered her and was quite willing to murder again to hide what he did.
In W.I.T.C.H. (unlike in the Animated Adaptation) Cornelia first sees Caleb in her dreams, and meets him for real later; the feeling became reciprocal.
In Scott Pilgrim, Scott dreams of Ramona and becomes infatuated with her before they meet, because Ramona's using his head as a Warp Zone.
In Amélie the shy Amelie would like to give Nino, her new love interest, his lost album photo back. Without having to speak to him. Naturally, this is true love.
The whole premise of Ben X is romance in an MMORPG. The main couple meet in RL only in the last scene.
In Don Juan De Marco, the title character falls, hard, for a centerfold model he's only seen in a magazine. After many attempts he manages to phone her- when she tells him to bug off, his response is rather disproportionate.
In Enchanted, Giselle sees her true love in a dream, and builds a statue of him, being certain that he both exists and that he wouldn't find this creepy. The statue looks as much like Edward as Robert, anyway (dark-haired guy with light eyes).
Subverted in French movie (two versions) "Fanfan la Tulipe", Fanfan believes a (fake) prediction done by fortuneteller Adeline. So, he believes he'll marry king Louis XV's younger daughter. But, he ends up disappointed after he meets her, and prefers Adeline.
Arguably in Just Like Heaven, one of the main characters is or seems to be a ghost. They meet because the other character rents her former apartment. Near the end of the film, they have fallen in love, but still technically never have met in person. When they do, it seems to be a Downer Ending as she doesn't remember him, but turns into a Crowning Moment of Heartwarming when their hands touch and she remembers him.
Harry: Okay! You're in love with her! But have you ever actually met her?
Ron: No...could you introduce me?!
In the movie The Lake House, the main female character has not met the man she is writing letters to, as he is two years behind her time.
In the 1944 Film (noir) Laura, the detective investigating the titular character's murder falls in love with her through his investigation, even going so far as sleeping under her portrait. Subverted somewhat when he finds out that she's not really dead and the victim was actually another girl the murderer mistook for Laura. The two actually do fall in love and justice is served to the miscreant.
In the French movie A Lovely Witch (Un amour de sorcière), Hot Witch Morgan tells to her infant son, Arthur, the story of a little witch. This witch fell in love with the portrait of a young man, and found a magic spell that would get her pregnant by him without actually requiring his presence. Then the little witch was punished with a mindwipe, and the portrait was also erased, save the eyes of the man. Later, Morgan meets and falls in love with Gadgeteer Genius Michael. Suddenly, we guess: Arthur was never seen with a father around him, and there is a portrait with only the eyes visible in Morgan's room. Eyes identical to those of Michael.
In Only You, 11 years old Faith hears in a spiritualism session her soulmate will be named Damon Bradley. Ten years later, on her wedding day, she gets a call from a guy named Damon Bradley. Naturally, she drops everything to go meet him.
The whole plot of Sleepless In Seattle. The official couple, Annie and Sam, meet face-to-face only in very last scene. Annie is engaged, and she has never seen Sam; she only knows his voice, thanks to radio. This doesn't stop her from breaking off her engagement for a guy she doesn't know yet.
The whole plot of You've Got Mail. Meg Ryan's character falls in love with a guy she's online dating.
This is one of the triggers for the plot of Somewhere In Time. The main character falls in love with an actress after seeing an old picture of her, making him use Mental Time Travel to meet her after he learned that she'd already died of old age.
In Terminator, Reese claims to have been in love with Sarah ever since seeing her picture, which kind of comes off as being creepy.
The troubadour Jaufré Rudel was famous for have fallen in love with princess Hodierne of Tripoli (of Jerusalem), after having simply heard about her. Even when he really met her he kept loving her and even died in her arms.
In the tale of "Maguelonne", Pierre of Provence, a southern French nobleman in Middle Ages, compares himself to Rudel. He once heard pilgrims talk about Napoli's princess, Maguelonne, and her golden hair. He falls in love with the description, rushes to Napoli, confirms his love for the princess, and she even starts to love him as well.
Countless fairy tales are about a prince falling in love with the heroine's portrait. For instance, in the tale of "Doe in the woods" by Mrs d'Aulnoy, the prince Guerrier (Warrior) falls for Princess's Desiree picture. Later on, the evil and ugly Desiree's maidservant came to Guerrier home pretending to be the princess. Poor prince believes at first he's in love with an inaccurate painting.
Also that Russian tale, Seagull princess : a prince discovers a lady's portrait in his best friend's room, falls in love with it, and immediately tries to kill his friend, believing it's his fiancee's portrait. Wrong: It's his sister's actually, and he'll introduce her to the prince at soon as possible.
In some versions of Donkeyskin the princess has never seen the prince before been asked to bake a cake for him. But she still puts her ring in the cake so he can find her later, ultimately marrying him.
The Egyptian tale of "Rhodopis" is an old Cinderella-like story, with even fewer meetings for the official couple. An eagle steals a sandal from Rhodopis, a Greek slave, then drops it in front of the Pharaoh. He is surprised by the tiny size and swears to marry the lady to whom it belongs... Never mind that all that he knows about Rhodopis is her sandal; he marries her when he discovers that she is the one who fits it.
"Yeh-Shen", another version of "Cinderella", does something similar with the king finding or being sold Yeh-Shen's lost gold slipper and becoming so fascinated with its tiny size that he vows to find and marry its owner.
Tristan and Iseult plays with this concept. King Mark insists on marrying the girl who left a single blonde hair on the edge of his window... except that the only reason he's thinking about marriage at all is that the barons want him to be, so he decides to choose someone impossible. But his nephew Tristan guesses that girl must be the blonde Iseult, and he brings her to the king. Then, well, you did read the title.
Alice and Jasper in Twilight. Alice can see the future, which is how she knew where to meet him in the first place.
In Belgarath the Sorcerer (the prequel to Belgariad), King Riva has interesting dreams about a particular girl — who turns out to be the titular sorcerer's daughter - the younger, mortal one Beldaran. They get married and start the line that leads to the protagonist of the main series.
Drustan falls in love with Ana due to seeing her in visions in Juliet Marillier's Blade Of Fortriu.
In The Vampire Diaries, Elena's best friend Bonnie, who is a psychic, reads Elena's palm and tells her that in the future, she is going to meet a "tall, dark, and handsome" stranger. A few minutes later, Elena sees Stefan for the first time. Elena instantly and immediately falls in love with Stefan the moment she sees him.
In Tom Holt's Mind Screw book Falling Sideways, the protagonist falls so hard for a portrait of a long-dead woman burned as a witch that he tries to get her cloned. After much confusion and many, many lies, it turns out he was genetically engineered to feel this way precisely so the entire plot of the book could unfold as it did.
Played with in Les Misérables. Marius and Cosette have only seen each other and not actually spoken, but they fall in love somehow. When Jean Valjean moves and takes Cosette away with him, Marius gets so depressed he does everything he can to find her, even though they've still exchanged nothing more than a few glances.
Eva Ibbotson's Magic Flutes has David Tremayne falling for a princess he's never met, just from pictures of her and others' anecdotes about her kindness and bravery. Thing is, he's the assistant of said princess's Love Interest, so his love goes unrequited.
In Someone To Run With Assaf follows a dog which is supposed to lead him to it's master. While he does so he speaks with people the girl knows, later even reads her diary and is already half in love with when he finally meets her. And he only falls harder from then on.
Possibly the uber-version of this trope is the legend of the (historical) troubadour Prince Jaufre of Blaye's long distance love for Hodierna Princess of Jerusalem and Countess of Tripoli (also historical). Supposedly Jaufre embarked on the Second Crusade just so he could meet her, only to fall sick on the voyage and die romantically in her arms upon his arrival in Tripoli.
Grace Greenwood's poem "To —".
We never met; yet to my soul
Thy name hath been a voice of singing,
And ever to thy glorious lays
The echoes of my heart are ringing.
Eragon plays with this a bit with the title character having visions of a girl in prison. He crushes on her and rescues her, but she's not interested in him in that way.
Emma: Emma Woodhouse feels Attraction Before First Sight towards Mr Frank Churchill. He's son of her close family friend, though they have never met each other. They are socially equal and close in age, and both are intelligent, charming and handsome.
In Lavinia by Ursula K. Le Guin, there's a sort of case of Destiny Before First Sight: Lavinia knows by her belief in prophetic visions that she will marry Aeneas even before he arrives in Italy, and knows that this is the right thing to do for the sake of her people; she rather loves Aeneas before meeting him, too, but that's a bonus.
Live Action TV
The song "Mystery" from A Bit of Fry and Laurie is all about the singer's love for someone who happens to live in a different country... and to be dead. And who probably wouldn't have liked him anyway. Hence the title.
Shawn of Boy Meets World finds a lost purse and, from its contents, becomes convinced that the purse's owner is the perfect woman for him. He's actually already met the owner of the purse's contents (the owner of the actual purse didn't own the contents), but didn't get to know her well enough to start a long-term relationship.
Paul falls for Echo after seeing a picture of her - though after he's told it's pathetic, he really does try to return to real life. Eventually he turns out to be right about Echo and him.
Both Topher and Bennett had crushes on each other before they even saw each other, having "known" each other through their various scientific achievements. After their first kiss, Topher admits he even had a crush on Bennett "back when I thought you were a dude."
Phil falls for Keely in Phil of the Future before they officially met in the first episode; his family comes to 2003 during Christmas, and Keely walks by. He becomes so infatuated that he goes back in time several times to fix a glass star Keely was responsible for as Pickford Yultide Princess that Pim broke (and keeps getting broken).
Barbara: And don't forget the star!
Keely: That's my favorite part.
Phil: I know. You were the Pickford Yultide Star Princess, after all.
Keely: That's right. Wait, we didn't even know each other then. How'd you know about that?
Phil: Well, see...I actually met you before you met me.
Pim: Met her? You followed her around like a pathetic puppy.
Phil: Psht. Sputters incoherently.
Pim: You were like 'Oh, we have to help the pretty crying girl!'.
In episode "Haven", it is revealed that Troi is due for an Arranged Marriage. When she meets her husband to be, she sees a bunch of drawings he made showing a woman's face from childhood to adult. The groom claims this is a woman who has been appearing in is dreams from a young age and always assumed it was Troi. Sure enough, said woman turns up later in the episode, prompting the groom to run off with her returning us to status quo.
Geordi LaForge falls in love with starship designer Leah Brahms after working with a holographic version of her. It makes things really awkward when he meets the real (and already-married) Dr. Brahms who unlike the hologram turns out to be bossy, cold and highly critical of Geordi's work (to makes things worse, she gets really pissed when she finds out about the hologram). However, they manage to become friends, and the final episode suggests they end up getting married in at least one timeline.
The TV series Catfish which centers about online romances runs on this trope. The premise is people who have fallen in love but never met in person. Every time, one of the potential people is hesitant to meet, because they are hiding something. Usually has a Downer Ending because the lies, even if for innocent reasons (such as insecurity about his/her real appearance or career), break the trust upon which the relationship was built.
Terriers, of all shows, uses this one. Britt saw pictures of Katie when he robbed her apartment, tracked her down at the bar where she worked, and asked her out. And immediately gave up burglary.
In the Wings episode "Ms. Write", Brian falls in love with "R", the author of some very passionate, poetic love letters delivered to his house by mistake. He eventually meets "R", who turns out to be a 12-year-old girl.
Bryce and Keiko in FlashForward (2009). Each even makes a trip to the other's home country in an effort to find each other.
The name I never whispered, as it echoed in your mind
The man I never was, the sweet thing that's not mine
I drink to you, I toast your name, a name that I don't know
The song "Haven't Met You Yet" by Michael Buble. Especially noticeable in the official music video, where the singer dances around a department store and sings about how amazing he and his future (imaginary) lover are going to be, including the repeated line "I just haven't met you yet"... only for him to wake up from his daydream and get out of the department store embarrassed. Except as he's walking out, he walks past and notices a girl that looks identical to his imaginary lover.
Another case of two people affected by this trope is the David Bowie video "As the World Falls Down" — a woman falls in love with a man (Bowie) when a photo of his face mysteriously materializes via her copy machine. The man is already in love with a painting of her. She figures out where he is, but only gets as far as opening the door before turning back.
"Even before I met you I was far from indifferent to you."
Mozart's The Magic Flute has the hero Tamino fall in love with Pamina from her picture, and she apparently fell in love just from hearing from Papageno that he's a great hero who's in love with her.
The Ming-dynasty play The Peony Pavilion (Mǔdāntíng) is about two people who fall in love without ever meeting one another: The girl Du-Liniang falls deeply in love the boy Liu-Mengmei in a dream and, knowing that there is no way the love can be requited, dies of a broken heart. She, however, leaves her portrait near the titular Pavilion. Years later, the actual Liu-Mengmei comes upon the portrait and gets romantically smitten. Du-Liniang is brought back to life by The Power of Love, and everyone is happy.
In Bells Are Ringing, Ella, as Jeff's telephone answering service girl, falls in love with his voice before meeting him in person.
In The Most Happy Fella, Tony falls in Love at First Sight with a waitress who can't recall his face, not even after he leaves her a tie-pin and a love letter as a tip. A few months of correspondence later, she travels to the Napa Valley to marry him, with a picture of the handsome young man she assumes is Tony but unfortunately isn't.
A quest in Fable II involves a man who has fallen in love with the long-dead Lady Elvira Grey. The player helps him by collecting her scattered body parts so she can be revived, Frankenstein-style.
This occurs in "Palla", a two-set book you can find and read in Morrowind. The story's narrator falls in love with Pal La after seeing a statue of her fighting the monster that ultimately killed her; being a necromancer, he sets about the monumental task of bringing Pal La back to life, so they can live happily and in love ever after. He finally succeeds, but before he can join his beloved, he finds out that Pal La was the monster. Who is happy to meet him.
In Quest for Glory IV it's possible for the hero to fall in love with a woman that he's only met in dream sequences. Also, for the first four games in the series, she's dead - but it's possible to bring her back to life and eventually marry her in the fifth.
Space Quest plays this. After a big mess involving Time Travel, Roger's Kid from the Future shows him a holographic projection of Beatrice Wankmeister. Roger is instantly smitten, and (contrary to what his kid states) doesn't forget his trip to the future. At the opening of Space Quest V, Roger still can't quite get Beatrice out of his mind. In the course of the game he meets her, and the pair start up a romance.
In Fate/hollow ataraxia, Bazett has had a crush on Lancer (aka Cu Chulainn) long before she summoned him - She fell in love with him when she read the Ulster Cycle as a child, and joined the Holy Grail War in hopes that she could rescue him from his early, unpleasant death.
They do later become an unofficial item and go on outings that both carefully avoid referring to as dates except when Rose's newfound drinking problem makes her late for one.
Vriska goes on to get a crush on Nic Cage, and then, more seriously, John.
Jane, Dirk, and to a lesser extent Roxy all fell for Jake just from chatting with him over pesterchum, plus Roxy for Dirk as well. It's even worse in Dirk's case, as he's separated from Jake not only by distance but by hundreds of years of time.
Kevin Kindle and Kell Dewclaw of Kevin & Kell met and dated online long before they met in person. This enabled them to get over the fact that Kevin is a rabbit and Kell is a wolf. The story starts one year after they got married, and they are still together 16 years later.