I have seen this fox before.....This is just a copy of 立羽's (Marvelous Grace/Tateha) fox Shiori from their "Kitsune Mofumofu 4" Doujinshi as you can see in here on page 7: https://hitomi.la/doujinshi/kitsune-mofumofu-4-%E6%97%A5%E6%9C%AC%E8%AA%9E-1465011.html

A shame it was stolen and not credited even to the point of the same pose, figure, and practically the same hair style...