Cel-ga Atume (Sato) used to allow people who had 
their own Yahoo JP IDs to bid on their own 
auctions, and then he would take care of the 
transactions if you would forward him the e-
mails.  However, he doesn't accept new orders 
anymore.

The other Celga (bustakei) doesn't allow this at 
all.  You cannot use your own ID and expect them 
to complete the transaction.  They will simply 
refuse.

I've seen auctions (BEFORE THEY END) where people 
would ask (more like beg & plead) on the Q&A page 
if the seller would make an exception and ship to 
the US.  It sometimes works, but not always.

Unless you know someone in Japan, you may be in a 
bit of trouble.