Chikan is a Japanese term for a fetish involving grouping and molesting others in crowded public transport. The term ‘chikan’ refers to men, while women who with this fetish are known as chijo. Chikan roleplay and fantasies are common in Japan, appearing in popular culture and in hentai, and brothels offer rooms decorated as train rooms to let participants live that fantasy. Outside of the realm of roleplay, groping a stranger on a train without consent is of course sexual harassment. Non-consensual chikan was enough of a problem in Japan that women-only subway cars were introduced to combat the phenomenon.