Some of it didn't go how I thought it would. It missed tying the whole thing to the series properly. The character I thought would do narration for the prelude section was narrating what felt like a recap of sorts, in which they could of tied the middle segment to it instead the title screen separates it.
I do feel that the voice actors for the narration (sub and dub) kind of got the short end of the stick by not getting to narrate the main segment (in the manga their character does the narrating) and one character that I thought wouldn't be in this popped up in the recap bit.....
I still enjoyed it but I kind of feel that they could have just played it off as him going through his memories and remembering a time that this other character told him about her life. It would have tied the film to the series and connected the front segment properly to the rest of the film. Also a little narrating from the prelude bit to the small future clip of the character the film started with would have tied it all nicely together and make it just seem like he was remembering her.
As for the prelude section, that part was practically spot on to the manga and very well done as was the after scene.