Can you tell more about his courting behaviour? If it's a sasayama subspecie, you should see that he places his hind leg on the head or neck of the female.
Aha! The foot on the head, the final clue xD
The Kanto race has a very similar courtship ritual but without the feet fetish.
The morphology and the behaviour coincide with sasayamae, i too think that´s what your animal is.
It´s weird, however, that his colors are so faded. Most sasayamae display stronger color changes during season, it may very possibly be the age.