Though I am not Japanese, just drop by to give some information which I know which may help to shed some light.
I don't have first hand account on these information that I have but they came from friends, articles and shows that I have watched over the years regarding about Japan.
I learn from friends who have travel to Japan - by the way they are guys, that Japan is a very cultural country. They do protect their Japanese way of life. They told me that there are places, like shopping, eating and yes even commercial sex, are only open to and serve only Japanese. One of them experience this personally. One day he went into a shop to look at an electronic item. The lady in the shop approach him. Using gestures, she poiletly told him to come with her. They took a while to reach another place where the lady indicate with the shop owner there that he can purchase that particular item he saw at her shop. And later my friend learn that the shop he enter is only for Japanese not for foreigners. But he was impress that he wasn't told just to leave or just being kick out by was escorted by the staff all the way to a shop that he can buy.
There was an article I came upon quite some time back. It was regarding about the Japanese sex life. The article wrote that even though the Japanese have a thriving porn industry, in reality, their sex life is almost none existent. They hardly have sex and most married couples lead sexless life. And this affected the birth rate and the government is concern about this.
Another point of note is about a show where Japanese woman are being interview. Some are married some are not. Those who are married shed light on their lives. The girl mention that the wife every morning have to make breakfast for the husband and when the husband are going out to work, it is a must to send her husband to the door. But it don't end there, the wife have to stand at the door to wave the husband off and remain there until the husband have disappear out of sight on the horizon and the wife can proceed back to the house. And from the women that are not married, did mention that they never saw their mother without makeup before even at home. One girl mention that what she know from her mum is that she only remove her makeup when her dad had already fallen asleep. And before he wake up in the morning, her mum will be awake to put on her makeup. And the girl also mention that she did ask her dad before and her dad say yah he never saw her mum without any makeup before even when they are dating. And the others girls too mention the same thing too about their mum. And those who are married also mention they never let their husband see them without makeup.
There was a JAV clip I saw many years back which have chinese subtitles. It was about a girl having her debut in JAV. And there was a scene where they already have sex and the guy ejaculated on her face. After that the girl just lie there and refuse to suck the guy's penis despite the guy telling her to do so. Then the director - I suppose so, came forward and tell the girl she need to do this. It is part of the practice in JAV that after the guy ejaculated the girl must suck the guy's penis. It is a sign of showing respect to the guy. Not sure if it was translated correctly but that was what I got from the translation.
There was also this show that I saw which the celebrities of the entertainment world in Taiwan mention. They once invited a big JAV star to come over to act in a short stage play. I can't really figure out who she was as the show is in chinese, but I reckon that girl they were referring to was Yui Hatano. But whoever she is, the girl left a very huge impression on them. They mention that the girl was very professional throughout the filming. She was always smiling and bowing. And even when on break, she never sat down, never take out her phone to msg or play but instead still stand with a very straight posture with her hands in front - the sort of pose you can expect from a Japanese elevator girl. And she only relax when the whole filming section ends and at the dressing room, they finally see her sit down and gave a sign of relief that the filming is over she can now relax and started to drink water and interacting with the people around her. And despite all the time her assistant was fussing over her on whether if she is tired, thirsty, was her scene too tough for her etc. She took all in her stride and told her assistant that she is fine and told her not to worry. The Taiwan celebrities was very impress with her professionalism and mention that they were more worry about her assistant as she was freaking out whereas the JAV star was as cool as cucumber.
And you may be wondering what have all these got to do with JAV? Well, from all these it do shed some light for me that it all boils down to the Japanese culture and the way of their up bringing. So what we see in JAV is the butterfly effect we got from that. Well that is my opinion and what I learn from all the sources that I stated above.
And yah really would like to hear from a Japanese person their opinion and really want to know that what are I have mention are really facts. Well I do trust my sources especially those accounts from my friends but for the other sources, not too sure as not sure if they are being said to up the entertainment value for the shows.
maybe judeo/christian influences have caused westerners to have too many hang ups about sex, the Japanese just seem to have less inhibitions in porn and yet Japanese are perceived as more reserved than westerners) many many interesting questions.
