Red Bean (paste) + Vanilla Ice Cream + Milk (optional)
w/o milk
w/ milk
The pictures don't look very appetizing, but it's good
Google doesn't do much better. I found something that looks worse, even suggestive. :S It's here if you really want to see it.
Anyway, the ice cream chills the red bean paste and gives it a creamy texture. Milk(little) is optional. It adds more fluid to the mix, but the interesting thing is that the water component freezes on contact with the ice-cream, forming something similar to crushed ice, and gives it all a bit more bite.