You can go to any 7-11, Circle K etc and pick up "porno manga" .. its right next to the womens fashion and golf ball of the month magazines.. all the sexy parts are censored. Surprisingly enough different countries have different rules on what is acceptable and what is not acceptable.
If some guy wants to quietly read censored porn do you really care that much? Would you rather have people blasting rnb out of the tinny speakers on their phones, throwing rubbish every where, being gobby shits etc?
And to the guy that complained about getting pushed around etc... is there a train network anywhere in the world that doesn't have that. The london undergound has that, the tokyo metro has that, the paris metro has that, the bay area BART has that. I've never been on a municipal transport network that wasn't hell at peak times. Sure you didn't have "oh japan is soo baaad boohooo" syndrome?