Sadly, those kinds of misreportings are common in other countries and places too. My own home of New York City has been hit by a number of underreporting scandals. I have no reason to believe they are less common elsewhere than Japan. So I still think national crime statistics provide the best basis for comparison.

Is the punishment for groping on trains still apologising to the victim on a train platform?

That. If you speak with Japanese women (in Japanese) they don’t feel safe at all and they have reason for that. There is a lot of perverts here. One day my girlfriend called because someone opened the door of her appartement. Another friend had a guy pretend to be the gas guy to enter their appartement just to retract when he saw the size of his shoes in the corridor. A female friend (foreigner, well endowed)... groped at the Shibuya crossing, etc. Even male friend have bad stories about guy trying to taxi them somewhere.

> It’s normal and unreported.

There is no question that victims of sexual crimes needs to be heard out more. However, your statement is an exaggeration to say the least. Groping is a frequent and well-documented topic on Japanese news. But as is often the case with sensational topics like crime, it is not as commonplace as you make it sound like.

I also doubt that the people around you were "unsurprised" to hear such things happening to your friend. It's just easy to imagine Japanese people displaying seeming indifference because of the sensitivity of the topic. At times, Japanese people can be reluctant to clearly express their opinions.