Terry's mom and I had to go to the Cambodian embassy today to get our visas (we're all going to Siem Reap next week) so we took a ride on the Hanzomon line, and were happy to find ourselves on the "Women Only" car. I had heard about these but this was the first time I'd seen one, probably because I'm rarely going anywhere by train at that hour, and like the HOV lanes at home, the no-men-allowed rule is only enforced during rush hour. Apparently there had been a bit of a groping problem on crowded trains, prompting transit authorities to create this safe haven. The official reason, according to the Tokyo Metro website, is that these cars were adopted "so that women and elementary and younger children can ride with a sense of security."
Here's a shot of the station platform sign that tells passengers where to queue up for that special car -- specifically where the doors will open -- and let me tell you, I rarely see a train here miss its mark.
Looks like an ad for sanitary napkins, no?