Japanese women typically seem to be more tolerant of P4P than American women, but I would still be cautious.
That's always been my perception. Back in my McJob days, most of the young gaijin male teachers and young Japanese female office staffers would hang out and get loaded after work, and any time the guys suggested we hit a pink salon or titty bar, the girls generally just laughed it off, if not downright encouraged it. Then again, it's not like any of us were upstanding paragons of virtue. Actually, the office manager also worked at a kyabakura after hours, and another of the girls worked a straight deriheru service at night and loved to brag about it the next day.
The topic actually used to come up a lot in discussions with female students, and being new to Japan, I was stunned by the number of girls who had an opinion along the lines of, "I don't care what my husband does, as long as he uses and condom and always comes home to me."
Two of my (ex) girlfriends, early on in the relationship, would ask if I'd ever done any P4P activities--in particular, if I'd ever been to Tobita Shinchi. I obviously said NO, but they both would suggest that it didn't matter because it was in the past, as long as I used a condom. But then again, this was while living in Osaka. I don't think any straight male in Osaka over the age of 21 HASN'T been to Tobita Shinchi.
My other half now has always assured me that no matter what I did in the past, it wasn't her business and didn't matter. Then again, she is pretty open-minded (by Japanese standards). We're going to hit Nana Plaza in Bangkok later this year just to check out all the trannies and other fun sights to be seen. She'd probably laugh her ass off if I tried buying one.
Stateside, back when my friends and I were in our late teens and early 20s, we often used to hit the strip clubs and bring the girlfriends along. The (female) strippers loved it and some of them would make out with our girlfriends. And after that, if it got the girlfriends all hot and bothered, we'd take them back to the car and fuck in the strip club parking lot. Being young and utterly fucking careless was awesome.
But I'm not young, anymore, and in my business information is the standard currency. I keep everyone on a need-to-know basis and as far as I'm concerned there are very, very few people who need to know anything at all. Being old and overly careful does indeed suck, but that's what the occasional trip back to Japan is for.