Actually, pretty easy to refuse this one.
Onechanbara is a japanese game where you play as either a sexy lady in a cowboy hat, her little schoolgirl sister or the moonwalking skimpy police woman. Right off the bat only the Bikini Woman, Named Aya, but you get to play as the other two later in the story.
Now, down to business, the story... The story kind of just starts outta nowhere, it opens with Aya in the shower in a glorious PG-13 cinematic, which means, no full nudity... *Cry* Well after some dialog between Aya and her sister, which is hard to get into because the game is not dubbed, just subbed, as they are watching the news, suddenly ZOMBIES!!! AHHHHHHH!!! And then they leave to go fight... ZOMBIES!!! AHHHHHHH!!! That's pretty much the beginning of the story, there are just zombies, and that is that.