I'm in agreement with one IMDB reviewer who said (paraphrasing) that it would have been better to leave the cinema after act 2 and imagine the rest. For most of the back half, what started out feeling like a potentially intriguing character piece devolved (my opinion) into a fairly generic thriller with extended manhunt/shootout segments. Right near the end, there _was_ one last swipe at character work—the reason I'm marking this whole comment as a spoiler—when Yoshii simultaneously mourns Akiko's death _and_ deals with the realization that she wanted his credit cards more than she actually liked him. He deserves it, really, but it's still a tough beat to watch. Yoshii's "assistant" has friends in high places, certainly, though we seem to get few clues regarding who they are. In the English subtitles on my Delta flight, the only real hint was the courier (?) suggesting requesting help from "the syndicate" when Sano takes the bag. As they drive off into the sunset, I'm left to assume that Sano has effectively recruited Yoshii to continue reselling on behalf of his organization, and that's why he's encouraged to make lots of money from now on.