Yesterday, commenter Bob Cap asked:

Whats going on with the Japanese sex robots......functional yet???

While I don't have any information about Japanese robots specifically, The Week has an article online covering the future world of robotic prostitutes:

What are the benefits of robotic prostitutes?
Beyond being tireless, "commercial sex robots would be free of disease and would reduce the trafficking of real people," write the study's authors, Michelle Mars and Ian Yeoman at Victoria University of Wellington, New Zealand. Human trafficking continues to plague every region of the globe, with conservative estimates putting the victim count at 2.5 million, according to the United Nations Office on Drugs and Crime.

[...]

What would future sex robots be like?
Mars and Yeoman envision "next-generation robots with human-like skin," offering intimate services like lap-dances and intercourse. The bots would be made with "bacteria resistant fiber that could be flushed for human fluids between uses," keeping them disease-free.

I'll tell you, nothing sounds sexier that a tireless robot made of flushable bacteria resistant fiber. However, the upside is that I'm relatively sure the human race will find a way to give robots sexually transmitted diseases somehow, which might slow their inevitable dominance over the planet.