A "Boarding point for ladies only" (女性専用乗車口) sign and man's shoe on the platform at Osaka Station (大阪駅 Ōsaka eki). During busy periods trains with women only carriages are run in order to avoid problems with women being molested by men on the packed trains. Outside of the restricted hours, men are permitted to use these carriages as well.
From Wikipedia (http://en.wikipedia.org/wiki/Rail_transport_in_Japan#Trains_and_crime):
One of the most widely publicized crimes committed on trains is chikan or groping, taking advantage of overcrowded cars and a reluctance for people to ask for help, or to jump to the aid of another. Typically, the victim is female and the perpetrator male. A recent trend for railway companies to promote their lines is to service female-only cars on some trains (typically during morning rush-hours and late night trains, and often the front or back car) and is quickly becoming a standard practice, especially among Tokyo's busy commuter lines.
Rotated 180° in CNX2