Japanese fads come and go....or sometimes they come and stay. If you live in Japan and want to share what is hip and popular at the moment, here is the place to do it.
I do not live in Japan, but try and keep up on Japan's pop culture as much as I can.
Right now I understand marshmallows are popular in Japan...and not the big sugar balls we have in the US, but smaller and much spendier.
Also I just heard about ice cream that doesn't melt today, but don't know any details.