As a fan of the manga and anime when I was young, I recommend watching this, even if it is just for the nostalgia. I enjoyed the summarized version of the story I used to love.

* The pacing doesn't feel too rushed even if they're leaving out lots of stuff out.

* Also, the main characters are well portrayed. I specially liked that the actor playing Yuu subtly let us know about his feelings, while the manga and anime were more Miki centered POV.

* The story feels a bit more dramatic and serious. I guess the movie has "grown up" along with the target audience from back then (me included hehe). You can still feel the same overall vibe, though.

* I also appreciated Meiko's story being adressed a bit and Ginta being Ginta :) Not bad that also some other characters made a cameo, but left me wanting a bit...

All that said, you don't need to watch the manga or the anime to appreciate this. It's a cute story worth spending 2 plus hours.