Cosplay (Costume Play) is popular in several areas in Tokyo. For me. I enjoyed seeing different costumes during my first year in Tokyo, but after that the fun faded away.
Here is an article about Cosplay, in case you were not aware of it.
Have you every tried it? What is your experience?
I'd say that I like to watch cosplay performances, but haven't tried anything of the kind myself. Who knows, never say never :)