Japan is a relatively safe country for women travellers, though perhaps not quite as safe as some might think – crimes against women are believed to be widely under-reported. The best advice is to avoid being lulled into a false sense of security and to take the normal precautions you would in your home country.
Foreign women are occasionally subjected to some forms of verbal harassment or prying questions. The risk of harassment is highest in nightlife districts, especially for solo female travellers. Local women tend not to wear low-cut or form-fitting tops; wearing one may draw unsolicited attention. Physical attacks are very rare, but do occur.
Several train companies have women-only cars to protect female passengers from chikan (men who grope women and girls on packed trains). These cars are usually available during rush-hour periods on weekdays on busy urban lines. There are signs (usually in pink) on the platform indicating where you can board these cars; children of any gender may also ride these cars.