Although I think the title was supposed to refer to the zombies, it could just as easily apply to the main characters into this horror adventure. Why would you decide to bring a security guard that you just murdered back to life? When fleeing him, why would you run into the graveyard with your vials of reanimation fluid? That aside, although I didn't see any hentai content, given the author of the software and the introduction of a schoolgirl, I'm sure it's in there somewhere.