All I know is that "chado" means "the way of tea" in japanese, and they have cool looking tea houses with dumbass doors you have to crawl in to enter.
I know nothing of this rare tea, but I'd guess any new novelty tea that no one has cared about before is bound to be in low supply, thus rare. I doubt anyone needs to carry magical crystal through poisonous miasma to find special trees that yield the white tea leaves or anything.
that was stupid, i apologize.