Japan. And the new virus would be J-virus.. and the name of the victims who get infected is called Gaijin. The victim's body parts will mutate into tentacles covered with white sticky stuff after you shot each one of them. Their melee weapons are katana, daggers, kusaragi, kunai, and other modern Japanese melee weapons.
How they spread the virus is depending on the gender of the victims.. if the victim is female, they spread the virus by raping them (or just kiss them erotically), if the victim is male, they spread it by simply throw their white stuff from their mouth into the victim's face.
In this game you'll be playing as a new Japanese guy who was an ex-Yakuza leader. His entire family are dead by the virus, that's why he has no choice but to kill his own family and try to survive. But he's not alone, there is also a beautiful and sexy Geisha who was an ex-assassin, so she can handle herself and also help him fighting these Gaijins.
For the combat, you'll be able to pick up the enemies' weapons after you killed them, i.e. if you killed a Gaijin with a kusaragi, you can pick up the weapon and use it anytime. There are also other firearm weapons you can pick up throughout the game.. whether you pick up from the enemies, floor, rooms, or suitcases (like RE6).
Well anyway, this is just my basic idea. Do you think my idea cool? crap? or just pure disgusting? lol
Or Ireland. The populace is ravaged; staggering without direction, moaning and mumbling incoherently, spewing acid-like vomit at one another... then the virus hits and peoples' quality of life improves dramatically.