User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-5043481-20130205170401/@comment-5043481-20130205181239

From what I can see you don't need one, it has the same amount of buttons as the PSP. we did just fine with that or ages. And in tri the second analogue stick was just an alternative camera control. So is the control scheme the same as the PSP on 3ds?