Beautiful animation - lack of character development

This is a beautiful movie with breathtaking animation. Also the idea behind the story is alright but I really had trouble to get feel any compassion for the main character.
I couldn't care less for the driven Mr. Morisaki of whom I at least learned a backstory which makes his actions seem plausible. No such backstory or any reasoning is provided for Shin and Shun (Prince *beep*
My biggest problem was however with Asuna whim I found to be rather annoying. Her lack of interest and missing compassion got her pushed around until the very end when she finally realizes why she actually came to Agartha… and even after that she gets abused!

This movie is in many ways (and this has also been already mentioned) a homage to Studio Ghibli and there is definitely potential here.
Im definitely looking forward to see more movies by the director Makoto Shinkai.