Chikan

Chikan (痴漢, チカン, or ちかん) is the Japanese term used to refer to frotteurism, or men who commit such acts (the term for women who commit such acts is chijo, 痴女).

Use this tag if the game in question has this type of harrasment as an important factor in its story and it goes beyond a simple one time attempt. Not as a passing joke or a reference.