In the Yamagata Perfecture in Japan, in the vicinity of the hot springs Ginzan the hotel Fujiya Inn has been created . Author of the project which brings beauty and modern Japanese architecture and design to the area is Kengo Kuma and Associates.
Love the Japanese idea of a window flush with the tub! Nothing says relaxation like a nice soak with the breeze :) (There'd need to be a tree or something though for privacy haha) . there is a Japanese Garden (patio) outside.