I personally love the concept of universal balance, hence: Yin and Yang.
Unfortunately, though your art is beautiful, it's aso very WRONG.
The real portrayal of Yin and Yang as people is the exact opposite of what you made. The woman should be in black and the man in white.
The art is original and the technique is amazing. I've seen a lot of portrayals of Yin and Yang but not many people draw them as well as you did.
The mans face looks a bit TOO creepy, and the woman is a bit TOO sad looking.
Overall, it's really great art. (But NOTE: man = white and woman = black)