I know there's a big show in Yokohama Nov 10 thru 12th. The big quilt festival is in Tokyo every January. As for shops, I was given this link a few years ago for my brother to use. He travels to Tokyo a couple times a year for work, and my sister in law and I give him lists and money. The link is still active, so I imagine a lot of the shops are still there. Enjoy your trip!!
http://floatingworld.typepad.com/flo..._shopping.html