The benzene opening, inspired by Uberdude and his post Feel-good moves - #20 by Uberdude
Requiring six stones, it’s less efficient than most diamond openings, including – probably – the “tengen ponnuki” (which is not, pedantically, a ponnuki).
It’s much more efficient, though, than the famous ten-stone HI formation.
Also, like with the diamond formation there are a whole series of progressively looser benzene / hexagon openings possible. Consider this one, a couple of lines out:
