It’s probably defaulting to the wrong encoding (iso8859-1)…
try Style * Font “xft:Aquafont:size=19:encoding=iso10646-1”
Edit: On second thought, I think morbusg is right, I don’t see the numbers in the title bar like what happens when it tries to separate wide characters into two separate characters. Aquafont fills in * for any missing glyphs, which is what I see in your screenshot.