Oh shit we in the CT.
That tells me that Japan is sort of OK with Westernized games but the West isn't (at least for games coming from Capcom). I mean when you break down the numbers, DmC in Japan sold almost as much as DmC in US... despite having less than half of the population.
Pushing and advertising games in Japan is a whole different beast than in NA. Capcom is one of the premier companies so they can literally bully retailers around to market their games, and hell, retailers will even take it upon themselves to heavily market a game with the materials companies give them if it means they get a huge shipment of whatever AAA game is in the pipeline (MH4, next RE, next SF, etc.)
Even now there are stores still advertising DmC, so it's not a surprise that the game sold like it did.