Onechabara Z will be getting an entirely different set of scantily clad vampire hunters as part of its third set of download content. D3 announced today that Aya and Saki, the original vampire hunters themselves, will be playable in the new DLC, which will be available on February 14.
The 800 Microsoft Point DLC changes the story to reflect the new sisters. You'll also find some gameplay changes. Achievement pursuers will find 10 new Achievements to unlock.