You can still find some old gropers travelling on the trains in Japan. The pink carriages for women with protect you from the leeches in peak hour...but not in the other hours - Beware of the wandering groper's hands.
I have seen the pink carriages for women in Tokyo, Osaka and Nagoya, available in peak hours mornings and evenings when the trains are packed and we are pushed into the trained by white gloved conductors.
With all the very short shorts that some young ladies are wearing in Japan in summer, thank goodness for the ladies carriages.
I was travelling on a train in a major city in Japan, reading a book. A middle aged man got on the train and sat next to me, the carriage was not very occupied. As it was a warm day, I was wearing a skirt that came to my knee and was totally absorbed in my very interesting book. Out the corner of my knee, I saw the man's hand moving from his knee, towards my knee. His hand seemed to be getting closer and closer and just as he went to grab my knee, I turned around and looked him in the face and said in my best Japanese " If you touch my knee, I will whack you with my book and call the police."
He went red, moved away and go off at the next stop. Fortunately, this has been the only almost groping that I have ever experienced and I have been traveling in Japan for over 20 years. An English female friend of mine, who is a fluent Japanese speaker was grabbed in the breast by a groper in a crowded Japanese train. She not screamed at him, but a fellow passenger called the police and he was carted off to the Koban (police box) at the next station.
If it does happen to you when traveling in Japan, have a good book ready to hit them with and get your cell phone ready to call the police.... They will be there at the next stop.