First, read chapter 01 of the manga. Then watch this movie. The film is beautiful, the characters are charismatic. Endo is well conducted... Or not. Compared to cap01 of the manga, they retold it in anime changing the beginning (obviously not to leave this spoiler). If you're curious to watch, don't think twice! I thought it was excellent (overall). Technically, it was well executed. The point, which made me write a review, is that EVERYTHING is implied. Thing you notice OR understand at first in the manga, for the anime it became a catchphrase to make you think, but unless you pause to think, the show goeson, so there's a lot to, those who watch without reading at least chapter 01 of the manga will be forcing themselves trying to understand, and with that they may miss important passages of the anime.

(Spoiler)
Like the explanation about Fatima.

Watch. You'll like it because it's good. But it leaves an impression that if it ran longer, it could better explain all the parts