Do really people in japan think the hymen is a "wall" to be pierced? That's terrible misinformation...
I think that's just a common misconception in general, not just in Japan. Nevertheless, I don't think that's what this manga was depicting. It seemed more like Nemo was going out of her way to deliberately break her hymen.
I know this is just porn, but I like to think that the message in the end is that losing your virginity isn't really a big deal, of course have sex with responsibility, but losing your virginity isn't really something magical or special, moust of the time you will lose it with someone that is a asshole and you just need to remember that this person did nothing special and you can just forget about then.
Well, sorry for going of topic in a certain way.
No, that's a great message. Just a shame that more stuff had the balls to say that.