These dogs are Shisar, the guardians of the Ryukyu (Okinawan) Islands. You see them all over the place in Okinawa, on keychains, t-shirts, and anything else that is sold on the Kokusai-dori (the main tourist street in Naha).
Of all of the Shisar statues that I encountered, I especially like these. They remind me of our Pekingnese dogs, especially Jane. That was one cool dog.
I just watched Kill Bill vol. 1 two days ago for the first time, and spotted Shisar in two different scenes. When Black Mamba is purchasing tickets for Okinawa (one way) a pair resides on the back shelf, over the shoulder of the booking agent. The more obvious scene, of course, is when Hattori Hanzo's steel is unsheathed for the first time. That's Shisar, imprinted on that legendary blade.
On that note, I am looking forward to part 2. I think I may have to brave first night crowds tomorrow, because I don't want to wait to see it!