Try Magicland, Ton Onosaka's shop.
http://www.nuuanu.k12.hi.us/nuuanuweb/asia.../magicland.html Not easy to locate the shop though.
When in Tokyo, make sure to go Tokyu hands as they have a wide range of Tenyo stuffs. Some Tenyo counters sells items made for magicians. These are slightly more expensive, not made of plastic and most of them are sold in Japan only.
Be prepare the spend a lot of money in Tokyo, its a very expensive city.