Wow, I think this... well... it's... this is basically a perfect movie. I don't mean that in the sense that everyone will like it, or that it's necessarily better than any other movie; rather, I mean that for what it sets out to do, there is nothing that could conceivably have been improved. And that's a lot of italics.
First off and most noticeable is the stunning cinematography of modern Tokyo. Every shot is a work of art, somehow getting the framing, focus, depth of field, colour, lighting and panning absolutely perfect every time. Coupled with that is the sound that manages to flawlessly toy with silence and foley in order to support the calm, relaxed feel of the movie.
Then, the acting. Frankly, Bill Murray and Scarlett Johannsen should have each won an Oscar for their respective roles. Every note is touched with perfect finesse, somehow keeping you completely entranced and fascinated by their every move, expression, facial twitch and meaningful gaze; their performances are the very definition of believable. I found it absolutely breathtaking, which is something I rarely say about acting.
Finally, the weight of the film lies in its story and script. I do not know how they did it; the relationship and the emotions it conjures are built up in the most natural and masterful way possible, somehow incorporating genuinely funny parts into the whole thing. The build up was so perfect and so unparalleled for me that I started worrying about how the movie would end. Answer: pure genius, and the best ending to a drama movie that I can remember seeing.
I'm still blown away by this film. Do not allow yourself to miss it, although be prepared for a calm and slow brand of masterpiece.
In a sentence:
Perfect acting, writing, cinematography... and everything, really. It won't work as well for everyone, but you cannot allow yourself to miss this on the off chance that it does.