[quote=@Willy Vereb]
<Snipped quote by Nerevarine>I thought your nation hated beastmen.
[/quote]

The non-Human people of Japan would probably fall under the catagory of Mutant (Human descendants with recognizable humanity; abhumans). Even the Kemonomomi are human enough to fall under the mutant catagory, though they may be seen as "lesser mutants" they certainly would not be seen as Yao Guai (beastmen). 

As well, the Han are not stupid, they know when to look past prejudices for oppourtunity when a friendly nation shows up among the agressive like Mongolia and Madagascar, or the fickle like Tibet. Japan is a good trade partner to fall back on if Tibet decides to cut off Trade agreements, and with them safe access to North India and Iran.