Yankī is a word that comes from Japan and is used to describe a particular kind of fashion and style that became popular in the 1980s. This style is inspired by American culture, particularly the rock and roll and biker scenes.
Basically, imagine someone wearing tight jeans, leather jackets, bandanas, and big boots. They might have spiky hair or wear their hair in a pompadour style. They might also have tattoos and like to ride motorcycles.
The term "yankī" originally had a negative connotation and was used to describe young people who were seen as delinquent or rebellious. However, over time the word has taken on a more positive meaning in some circles, and yankī fashion and culture is now celebrated as a unique aspect of Japanese youth culture.