I'm guessing he's another monster bachelor, to balance out the two monster bachelorettes? He certainly looks it by those ears, and that might be his monster form on the edge of shot there. Also, he looks distinctly like a rajah, which is a look we've never had in Rune Factory before.
So they've got nightwear instead of swimsuits now, have they? Or perhaps more likely as well.
Only in his official art though, strangely enough. In his in-game art he looks rather sour-faced. Not nearly flamboyant-looking enough to be fabulous. Although maybe that scowl isn't his default expression.