When I took the kensei express from Narita airport to Tokyo, I met an American living in Tokyo who recommended me cafe where local Japanese people and foreigners met to improve their language skills. Since so far I couldn't really communicate with the people from Tokyo because my japanese vocabulary is limited to "konnichiwa", "arigato gosaimasu" and "sumimasen", and especially since I wanted to know the local people better, I just gave it a try. It was a little bit hard to find, because it's on the fourth floor and doesn't have big billboard sign. When I came there were only a few people, but after a while the place filled up pretty fast. I really had a nice evening and met some very interesting people like a japanese man who spoke very good French and even knew songs from "Charles Aznavour" by heart, a Dutch "Go" player who had won the world championship, or even a very nice japanese girl who used to be affiliated to the famous breakdance "Rock Steady" crew in japan just to name a few.
It is certainly not the usual thing people do when travelling abroad. But for me it was one of the best experiences I had in Japan. If you have a chance to cone to Tokyo, you should really give it a try. The place is called Micheyhouse (www.mickeyhouse.jp) and is located a little bit north of Shinjuku. The exact directions can be found on the site.