I found this place by accident. I was looking for another place called marugo5, which had incredible fruit and vegetables smoothie btw, and on my way there, I walked passed by this beautiful tea stand.
It’s called hachiya. It’s a small tea stand in Daikanyama. You can access it both from Daikanyama station or Ebisu station. It’s around 5 minutes walk from both directions.
You should try it, they are really good!