A Dutch-Japanese phrase book, compiled in 1770 for a trade legation from Holland -- the only Westerners permitted to reside on Japanese soil by the xenophobic shoguns -- had a mere 80 phrases. Its brevity suggests a paring down to the absolute essentials of speech needed to get by with the locals. Yet eight of the phrases -- an eye-catching 10% of the total -- pertained to hiring the services of female companions. These included a scripted exchange that would not be out of place in one of the more free- wheeling modern guidebooks for Western travelers to Thailand, say, or the Philippines: "Do you like that girl? / Yes,...