Unfortunately, it's the NEC SuperGrafx, a souped up version of the PC Engine (nee TurboGrafx-16) that was never released outside of Japan and has a meager seven titles in its library. Even less exciting is that the first SuperGrafx release is Daimakaimura, known as Ghouls 'n' Ghosts on these shores. That particular title has been available on Japan's Virtual Console service in its Genesis form since July of last year — and for 200 yen less!
But hey, at least things are expanding. Any chance we can start getting some Game Boy Advance games from the VC? Pretty please?