女性専用車両 ~women's only train car~

During the peak hour in weekdays (morning time), you'll find this "women's only train car".

Is this very unique in Japan?
Taiwan introduced this few years back but took it back. They said it's a reverse discrimination towards men.
In Japan, "chikan" -pervert- is a serious social problem and end up in making this kind of procedure. Oh.. such a shame.