Sabukaru

Sabukaru (サブカル) is a Japanese slang term that is commonly used in the sense of "alternative fashion" nowadays. Initially, the meaning was more along the lines of "hipster" with the term being used as a label for those who only follow obscure trends and avoid everything mainstream.

"Have you noticed the wierd tracksuit trend that has been popular lately?"
"Ah yeah, it used to be a Sabukaru thing, but now that it's popular they no longer wear those."