Falling in love is uniquely human. Or is it? Could you teach a program to love? Writer/director Spike Jonze doesn't attempt to answer this question, rather he simply follows the man who falls in love with Her (an advanced operating system).
In a future where technology has become even more commonplace, Theodore (Joaquin Phoenix) has a job where he writes "handwritten" letters. At one point he reveals that he's been writing letters for a man to his wife for a number of years. He's written hundreds, maybe thousands of letters, all seemingly intimate. He's lonely, as he's separated from his wife (Rooney Mara) who accuses him of not being in touch with his emotions. Perhaps it's quite the opposite, he feels so much emotion at work, that he doesn't know how to express it personally anymore.