Rose and Camelia
It's a... slapping game, set in Victorian times. And it's sick. You have to use your mouse to slap your opponent, and evade her slaps. If you evade successfully, you can do a quick counterslap for maximum damage
SLAP!!!
And it would be perfect for the DS.
Of course, I may be a year or two behind on the releases, and a similar game may have been released already, along with three sequels and a limited edition DS Lite, I just don't know.