There's just no nice way to put it. These girls are wearing blackface.

Manba/yamanba (there is a difference - the former has makeup above and below the eye, the latter only above. Subtle!) has got to be one of the most messed up fashion trends that I have ever seen. Don't get me wrong - I love some extreme fashions and think there's a lot to be said for creativity. This is not creativity. This is carbon-copy bimbos in blackface.
Social studies lesson: this trend falls loosely into the gyaru (literally "gals") subculture, and is an extreme version of ganguro ("black faced gals"), which seeks, theoretically, to highlight the beauty of tanned skin and to embrace the attitude of a typical California valley girl. I think it's kind of cool that these rebels took the age-old idea of pale skin = beautiful and turned it on its ass, but then it got taken way too far.
It is also worth noting that I was originally only going to post things that were for sale. I thought twice about this one, and then found out that they are for sale. It's not prostitution, though. It's "compensated dating," which is an entirely different thing.