I don't think this is a fake. But nevertheless, 
settei set (character settings & layouts) were 
normally available in only 'photocopies'. 

Like Fushigi Yuugi, Ai No Kusabi, Kizuna 1 & 2, 
Hana Yori Dango, Yami No Matsuei and several 
others I have seen were all photocopies.

It is rare for someone to have the originals 
(mastercopy), and besides those doesn't come 
cheap.

I think that there are several settei sets out 
there and not just one 'photocopied' copy by the 
production. (Let me know if I am wrong - I have 
seen several settei sets from Fushigi Yuugi 
before)

And it's better to ask the seller the source and 
also it's authencity. Whether or not, the 
photocopies were made by themselves or ...