Like the sashimi made from the poisonous puffer fish and those DoCoMo cellphones, there are some things in Japan that you'll see there and nowhere else.
Take this volume of Tokyo Express as an example. Our friendly neighborhood pervert orders up a woman from his PowerBook and quicker than you can say hentai Who-Kah pops up from thin air.
Who-Kah will have particular appeal to gaijin who like the docile, submissive type who come with their own wardrobes, not unlike a Japanese Barbie. In this case, she appears in a harem costume, a la 1001 Arabian Nights, and continues in her scene to fuck two men.
Unlike most of A6's other offerings, there's a semblance of a plot, though goofy in a comedic way, and the addition of subtitles are welcome. In fact, the subtitles also appear in the behind the scenes footage.