Its interesting that you mention a possible Japanese connection for Winkle. I'm only 50 pages into the book, but the initial description of Winkle makes me think of a Raccoon Dog: http://en.wikipedia.org/wiki/Tanuki
4 quoted lines
As to Bax's familiar, Winker/Winkle suggests a link to the story of the Urashima Taro, a Japanese Rip van Winkle who went away to fairyland for a few days and returned home only to find years had passed.
Strengthening this
supposition is the second half of the fox's name, Inari, which refers to a Japanese god of success & prosperity, often depicted as an old man riding a white fox.