I don't know who he is either but I remember
seeing him for sale and thinking he was a cutey ;)
(at least I think it's a he! *l*).  The character
design is really familiar (reminds me of
NightWalker) ;)

I haven't bought any unknown cels yet but within
the last month I've bought two cels from shows
that I haven't seen.  Maybe it's contagious..