I was really struggling in the first 15-20 minutes of this movie because I could not follow who was who, and what they were doing, or why they were doing it. So many characters are thrown at you with no background or explanation. However, there was a point when I started to say..."wait, I think I might understand some of the things going on now!"
The second act is where I was totally on board. The sci-fi super-power element of the plot had me intrigued. I was worried about Tetsuo, and was fascinated to see what would happen next. Sadly, the third act kind of lost me again. There's some good stuff going on in the climax, but then there's a lot of other stuff that makes no sense to me. I needed someone to just explain what was happening and why but the movie wouldn't offer that to me.
In a weird way Akira felt like watching a sequel without seeing the original movie. There was so much backstory that I wanted but this movie glossed over it as if I should already know all of it. I could see that Akira is probably a film that rewards repeat viewing so you could dig into it. The style is just one that I don't particularly love, so I doubt it's something I would personally explore further. I can see where people would be passionate about Akira because it is one of the best Manga/Anime films I've watched.