Sukeban (スケバン) is a japanese fashion derived from the looks of japanese girl gangs. The term is a slang that translates as "girl boss" and is mainly used to refer to a violent feminist movement that emerged in Japan in the late 60s. As male gangs - also known as yanki - originally didn't allow female members, the girls started a distinct identity of their own.
As most members of girl gangs are often still in school age, they still have to wear school uniforms most of the time which are modified in order to show off their own signature styles: blouses are cropped to expose the the bare waist, skirt lenght is increased, loafers are replaced by sneakers. Another key feature is the long customized coats which feature feminist symbology and anarchic messages in kanji.