Story: 8/10
Art: 7/10
Characters: 7/10
Quality Polish Edition: 9/10
Enjoyment: 7/10
Overall: 7.6/10

As of this post I have only read volume 1 of this 3 volume manga series. I have read the novel, but not seen the film.
I absolutely fell in love with the novel and the depth of the emotions presented there, which can really only be achieved by its first person narrative. This manga adaptation is good, with clean art and page layouts, but so far it's going through the story just a *little* bit too fast, and I find myself not quite as invested in the manga versions of these characters, who we don't get to have such an intimate relationship with.

Still, for a manga adaptation of a movie/book, it's actually very well done, as most manga adaptations of existing works tend to be quick cash grabs with sloppy art and page layouts. So its definitely worth a shot, but seriously, read the book too.