Byousoku 5 Centimeter - Hoshi no Koe - Hoshi wo Ou Kodomo - Kimi no Na wa. - Kotonoha no Niwa - Kumo no Mukou, Yakusoku no Basho - Exhibition of Makoto Shinkai - from "Hoshi no koe" to "Your Name." - official catalog (Bijutsu Shuppansha)

I already have the other Makoto Shinkai background artbooks, and in this book there's a repetition of the same art, but some are bigger and however in this one there are "screenshots" so there are characters not only background. however there are animation keys, sketches and character designs. sure the interviews would be interesting ;)
being a fan, for me it's worth it, considering the affordable price and the dimentions of the book.
uploaded some pics ^_^
more pics on my tumblr: part 1 part 2