Japanese bondage developed in a country where metals were scarce and therefore chains and metal restraints played only a small part. They still appear only rarely. In China things may have been a bit different but I have little information. Certainly Chinese handcuffs etc. are made in more modern times - see <www.thehandcuffshop.com>

In the West, handcuffs have all sorts of symbolism and a whole bondage sub-culture of their own.

harper