Im just back from Mickey House Conversation Lounge, and I just wanted to recommend it to anyone in Tokyo right now. Its free for English natives to go in, and you can practise Japanese, and English alike. Its a good way to meet people - a thing I find hard in Tokyo. They also have special nights for French and German, or any other language you require - just let the boss know and he:ll advertise it on their website. Its an extremely friendly place, much better than another conversation lounge I went to recently... :(
To get there, go to Takadanobaba (2 stops from Shinjuku on JR line) , take the Waseda Exit, and then walk down Waseda exit towards Wendys and the AU phone shop. Mickey House is on the 4th floor near here, so look up and youll see the signs in English!! Its about 3 mins from the station.