Izaya got it for me. It is from China, apparently.

[It really is quite nice. Zelda's no idiot though, she checked it for any sort of strange drugs that might have been painted on the inside of the cups. At the point that he'd given it to her, Izaya was already starting to express his jealousy over her friendship with Shizuo. She should have paid more attention...]

It's really a lovely set. I had no idea other worlds put so much time into them.