People have been talking about different versions and stuff. And how Natsume didn't know anything about it until referred to as HMDS.
I'm here to resolve this. I have done things with both Natsume and other companies including IGN and Nintendo.
In a way there are two versions. Japanese and American. They both have slight differences. But not much.
Natsume didn't know about HMSS because that's the Japanese version. Natsume isn't doing the Japanese version, only the American version which is being referred to as HMDS.
HMSS= Japan, Marvelous Entertainment
HMDS= America, Natsume
Get it? And the versions aren't very different, don't worry, don't buy both. It's just translation, the name of it, and some small graphics changes (the characters mostly), but not much, not enough to make a different game play experience.
So there ya go. Reply with any questions, comments.