Tokyo, JapanLike thousands of other Tokyo visitors on a recent summer day, we beelined for Asakusa, a popular tourist district. My companion and I were drawn not by the neighborhood’s famous Buddhist temple or its renowned geisha shows but by ivory. Banned in much of the world, here in Japan ivory is still sold openly and legally.

The hunt didn’t take long. Weaving through selfie-snapping crowds, past the thunderous booms of a live drum band and the tantalizing smells of freshly baked takoyaki, we stopped at random at a shop to ask for directions. We’d heard that a particular jewelry store nearby sold Chinese-style ivory jewelry. The shopkeeper shook his head: He didn’t think that place was around anymore.

“But if it’s ivory