This is a strange one.
Produced by Takeo Organic tea farmers at the foot of the Suzukasanmyaku, in the town Geino Mie Prefecture.
It is semi-fermented and is somewhere between oolong and black.
The taste is very sweet and minty. Goes perfect with pastry :)
Can get it here straight from Takeo family themselves.
Use google translate. The page is in japanese only.