Or does this game take long after HD, and represents another chance after it was defeated the first time? I'm guessing that the second game takes place long after Dawn of Sorrow - otherwise they could have probably just used Yoko if they needed a female researcher haha. Long enough that Yoko is retired but Genya is still employed?
The only possible place I can see GoS happening is before Aria.
On Genya's description it says that he's the
only one with power to stop Dracula, something that is not true when Julius Belmont is around -- hence he must be out of commission somehow, something we know was true before Aria.
Then, the story says that Genya received a letter that came to "put an end to the peaceful era" when the story takes place. Well, the castle reappearing on Aria and two dudes who can inherit Dracula's throne going to it is a MUCH worse threat and would have put an end to that era already if GoS happened
after Aria. So this little story intro makes not much sense if it comes after Aria.
If it comes before Aria, then everything fits. The peace is ongoing and Genya really is the only one who can stop Dracula during this time.
.....what is throwing me off is the existence of Lucy's organization to "fight Dracula". There would be no need for such an organization if Dracula was indeed permanently defeated as the story says. But then again, the same story does put the book where the castle can revive along with a depiction of Dracula as the centerpiece. So this could be relatively meaningless as the book represents "Dracula" in a way.