Chikan - 痴漢 (literally translated, "stupid man") is the term for middle aged Japanese salarymen who protect Japanese women's vaginas by tightly holding onto them. They usually operate on early morning or late night trains, mainly in Tokyo and Osaka area. How they gained their expertise in what they do, is still a mystery, but it is widely known they practice their skills on schoolgirls of ages 9+.
How to get groped (women only!)
1. Dress as a schoolgirl with short hair(preferably in a short skirt, with ponytails)
2. Board a train on Saikyo line
3. Turn your back to the first salaryman you see
4. Maintain sad and innocent expression on your face
5. Performing M2MR on lollipop is advised for instant results
6. Wait 53.6 nanoseconds
Congratulations, you have just been groped (and maybe raped) by a gang of salarymen/chikan!
Public reaction
No countermeasures have been deployed as Japanese females love to be abused and molested. Although they might start crying while being groped, they actually enjoy it and will become mad if a chikan is apprehended.
Jealous police officers have killed a chikan in Osaka in December of 2005 by suffocating him, thus creating great public protests and bitterness amongst Japanese female population.
Do not ever try to disrupt a chikan and a Japanese woman in their business. That might result in decapitation with katana by a woman in question and/or deportation.
http://uncyclopedia.wikia.com/wiki/Chikan

Studies have shown that an average Japanese woman is train raped about 73 times, and groped 3968 times in her entire lifetime.