Picked this up off the weekly Sun 2chan thread.
I ask Google what it was from and IT explained it is from a PS2 game called Vampire Panic. Apparently VP is not a very popular game. Pixiv cares very little for it. Youtube knew a bit but the particular playthroughs cared nothing for the details (Corruption)
Basic premise is a Vampire is preying on a town and 3 vampire hunters arrive to stop him. The heroes and heroine much fight through monster to rescue the townsfolk from said monsters and vampire(s). Interesting enough if you beat it you get to play the Vampire Side. Playing this you basically go about preying on bystanders and seem to get a drop down list on what to do with the drained corpses of men, women, and children (children seem to be delicacies...creepy) Some choices include charm, others some form of ghoulification, and a few that hint at vampires. Pretty dark and intersting given the fact the cliched anime video game vampire character basically can corrupt anyone including the heroine though Youtube denies whether or not this fact is indeed Fact as it does not show a video of such a transformation just ryona.
Great concept.
Rather bummed I can't find out more on the heroine Mary's bad end fate. Looks pretty cool...
http://vampirepanic.sega.jp/