My fav caffeine treat in this city is to come here for a "bulldog" (double espresso with a smallish amount of steamed milk - less than a latte but more than a macchiato).
As others have warned, it's cash only. To pay, you put your money down onto a plate on the counter, and they pick it up from there. Your change is delivered the same way.
I believe this is in the Japanese tradition, although I wouldn't be surprised if the owner insisted on this just to mess with people. I get the feeling he's one of those people that gets super annoyed by everything. Don't bother trying to chat to him, as he will probably find it...very annoying.
Whatever else this man is or does, he simply cannot help making (and teaching others to make) and selling really really REALLY fantastic coffee.
So: steel yourself. Take out some cash. And don't forget to try to the cheese croissant.