Jouhou -- A much more functional way to block the Summer Sun -- is to take advantage of the relative verticality -- so put a roof or awning over each window
Considering the number of buildings I've been in where the awning is practically nonfunctional due to incompetent design, I'm going to have to disagree with the notion that they are "more functional" than a design that actually accounts for the actual path of the sun (which is trivial to calculate in our modern times).