This over 400 year old unique market, Boroichi (rag/junk market), takes place only twice a year, and I was lucky enough to be there when it was going on. A friend of mine told me about this market and we went together. It was so much fun making our way through the huge crowds, they say over 200,000 people visit a day, to look at all the amazing wares. Navigating a crowd in Japan feels more like swimming in an ocean than driving in a traffic jam, because of the politeness of the people and their natural sense of walking in a certain direction and immediately being on the left or right side of the path depending on the direction.
Most of the items at this market were antique or handmade, which of course makes them extra special. It also has street vendors selling typical foods and drinks of the region. Most items I bought in Tokyo, I got from this market. It really is exceptional, and a must do if you are ever in Tokyo at the right moment.