It is a wonderful quilt show. I went a couple of years ago and some pictures are here.
http://www.quiltingboard.com/t-28804-1.htm
Be prepared to be amazed at the workmanship and artistry at the show. The smallest section then was the machine quilting. The hand quilting is fabulous.
Prices for fabric in Japan are very expensive. Quilt shops are few and far between and hard to find. As in most things the shops are small and will specialize in one or two things. There are fabric stores and you can ask about the cotton area. Use the phrase "patch work" instead of quilting as that is how it is referred to.
It used to be that you could buy used kimonos and remnants inexpensively but they have gotten onto the quilters and are now sold in scrap or assorted bags.
Word for cotton is dasshimen, silk is kinu/shiruku, polyester is poriesuteru (they don't have "L" in their language).
Enjoy the show!