The Gyaru
tag is wrong.
The character Mishima is obviously inspired in whatshername from "The Guy She Was Interested in Wasn't a Guy At All" series. Y'know, the record store girl who likes rock and looks like a guy.
But that's totally 100% not a gyaru.
Mishima's casual look can be called rocker style, grunge style, ghetto style, soft butch style, oh, lotta things—but she's nothing like a gyaru.