It's 3 guys, 1 girl. This has been oficially confirmed. The black mage guy that looks like a girl is named "Arkus"

Quote Originally Posted by Necronopticous
That was beautiful.

"It all began with a stone, or so the legend says."
Really, does it say that? I can't view the site myself, but that quote is EXACTLY how the narrative begins in the FFXI intro movie.