I had read about this place on other blogs and I was hesitant to go there. Coffee is not my special interest so why go and seek it when travelling around tea-territory? But I have to say, even if you will be surrounded by western tourists (not masses of them, but there were no Japanese when we visited) and expats, the place is a gem!
The one-man café serves only espresso coffee (and it’s variations with milk) and small cubicle shaped custard cakes. My man said that this was not only the best coffee during our trip but simply a great cup in general.
Omotesando Koffee is not easy to find, I tried to remember Heidi’s instructions by heart, since my Japanese data for my smart phone was used up at that time. I succeeded finding it but that was only partially thanks to my very good sense of directions and mostly due to a good portion of luck (following a group of smart looking French people who walked very determined past us in a small alley- “where else should they be heading?!”, I thought) This is what it looks like from the street, maybe that can help you as well:
somewhere in Omotesando, Tokyo
find a map here