A middle-aged actor and the wife of a photographer meet while on business in Tokyo. They strike up an unusual friendship in the hotel bar that helps them both overcome boredom and loneliness.

Set in Los Angeles in the slight future, Theodore, a complex, soulful man who makes his living writing touching personal letters for other people. Heartbroken after the end of a long relationship, he becomes intrigued with a new, advanced operating system, which promises to be an intuitive and unique entity in its own right. Upon initiating it, he is delighted to meet "Samantha", a bright, female voice who is insightful, sensitive and surprisingly...