In the days of old, there was a goddess who fell in love with a noble mortal. This would lead to great romance as well as great tragedy...as well as a legacy, leading all the way up to the present day. Now, demons from the underworld intend to subvert the human world, and the time has come for the twins Ai and Mai to take up the legacy. Trained by their grandmother since childhood, masters of the martial arts as well as the ancient Tenjin dances, they are the Twin Dolls, the Earth's best hope to stop the forces of the underworld. This is not to say that it's an easy job. The demons, led by the great Oniyashi Doji, enjoy seducing and enslaving young human ladies and using them for their own ends, and they also intend to make sure Mai and Ai are taken down in some perverted but permanent way. And not only that, Mai and Ai have a charge: they have to ensure the safety of the oversexed little half-demon Onimaro, who is destined to end the war between the demons and humans once and for all, who himself is enough to try both their nerves. This ain't your average fight, but then, these aren't your average fighters either.