Sex sells! And nowhere in the world does it sell quite as well as in Tokyo — or so it can seem.

Pornographic magazines by the armful can be picked up in most convenience stores, not to mention "exciting comics for men" boasting adult-themed manga and sections devoted to "delivery health" and other sexual services. Touts brazenly beckon passersby into neon-lit "soaplands" and other risqué establishments in the capital's seediest areas, and Japanese-produced Internet porn offers up some of the filthiest, weirdest fantasies out there.

Japan comes in a distant second in per-capita spending ($157 in 2011) on pornography after voracious South Korea ($527), but when it comes to comparing the sizes of the countries' homegrown porn industries, there's no contest. So prominent is Japanese porn online and on DVD that claims of Japan, with a population less than half that of the U.S., producing twice as many adult movies as the States are not hard to believe.