Yesterday I brought you one of the cutest, least expensive costume/statue type of things I've ever seen: Danboard the cardboard robot. This time, it's one of the most realistic, scariest demon statues I've seen in person.
I saw it in a different location in Akihabara a couple weeks later, but again without any signage to indicate its origin.
Anything geeky probably gets big in Akihabara. There are other otaku hubs in Tokyo and Japan, but nothing compares to Akiba. So I've seen a few promotional statues, cosplayers, and other promotional activities while exploring the shops. I won't guarantee you'll see something, but Sundays are a good bet (and the most crowded leisure/shopping time anywhere in Japan).