Spike Jonze's newest film, “Her,” is as much about relationships as it is about introspection and technology, and how the two intertwine.

Theodore Twombly (Joaquin Phoenix) is equipped with an almost comical mustache, pants hiked up to the peak of Mount Everest, and a weary face that communicates the desire for honest intimacy but is hesitant to give it.

In a Los Angeles of the future (which resembles Tokyo in some respects) technology is at an interesting point: Think of it as perhaps two or three steps from where we are now. The purchase and installation of a new operating system gets the story rolling: for, unlike our current oh-so-cooperative OS's, OS1 is sentient. And her name is Samantha (voiced by Scarlett Johansson).

Twombly, for all his insecurities, is a poet, a writer whose mind is stuck – for better or worse – in the romantic mindset. Phoenix's mesmerizing performance is layered and ­nuanced. Unlike many other ­actors, Phoenix doesn't play awkward or anxious or “that guy with intimacy issues”; he is able to fully inhabit them.

Johansson on the other hand has a difficult role. Her unique, velvet-torn voice has to do all the acting. Not only must it be emotive, but it must communicate a wide range of ideas that Jonze needs to convey throughout the film. She pulls this off with flying colors, seducing the audience as much as she does Theo. The rawness in Samantha's voice adds vulnerability and nakedness, painting the portrait of a woman with no body but still in full form.

When I heard about the project a year or so ago, “man falls in love with his Siri-like OS” struck me as a self-righteous comedy about the dangers of obsession and addiction. But what Jonze has created is something more raw and honest. He doesn't lecture. He, instead, fights for both sides, possibly even settling on the side of legitimizing the relationship people have with ­technology. It is undeniable; technology changes us, and the way we interact with it has become even more complex. So if it is real for the user, isn't that all that should matter?

Jonze and cinematographer Hoyte van Hoytema pay close attention to details and anomalies, from flying specs of dust to falling droplets of water in the shower. The glow of the film that bounces off every not-too-futuristic surface is not limited to the cinematography, but also shows itself in Arcade Fire's score.

Giving the film a central warmth that seems to bring everything full circle, the band imbues some life into the film. Karen O's sweet and melancholic “The Moon Song” completes everything.

Jonze plays the relationship between Theodore and Samantha straight. It can often be refreshing in its sense of humor. But it is real. It is a relationship more elaborately and minutely detailed than most on film and television. You feel it in your soul. “Her” is destined to go down in history as one of the greatest cinematic romances of all time.

Few films have felt so personal, to me and to the director. Few films can so immaculately channel and portray romance in all of its hesitancy and honesty and beauty. It may be my favorite film of the year. Like falling in love, “Her” is intoxicating. Maybe what the film is saying is, “The only affair that matters is the one that means the most to you.”