Theodore Twombly earns his living by writing handwritten letters, which have become something of a rarity in the near future. And in these years, people's jobs are now performed by computer programs. After divorcing his wife, Theodore starts living alone in an apartment, and one day his life changes along with a technology advertisement he encounters. A new operating system that offers a perfect artificial intelligence program introduces him to Samantha, an extremely attractive woman. Samantha, a virtual being and just a voice, introduces Theodore to a completely different reality with the questions she asks about the world and life. Theodore, who is in a severe depression, Decently begins to realize the pleasant aspects of life, while the relationship between him and the artificial intelligence program becomes increasingly strange.