My brother works as a counselor for troubled teens and pre-teens. The precise nature of the "trouble" varies a lot. It has been as mild as truancy, or as serious as arson or armed robbery. Anyway, he recently started doing in-home visits with the families, and he told me this story.
He went to see one family, and the mother had huge tattoos all over her upper arms. She told him something like, "I just had these done, and they still kind of hurt." My brother tried to casually look at the tattoos to see what they were, but without seeming like he was staring. He was surprised to see that covering one of her arms she had a picture of a naked woman with enormous breasts. And he could not quite tell what the other tattoo was, because her shirt was in the way. So he asked her, "uh, so, what do those tattoos represent?"
She said, "Oh, you know, it's hard to explain, it's like the Yin and Yang!"
I'm guessing the naked woman would have to be the Yin. I wish he had found out what the Yang picture was, though, because now I'm curious.