Bangya
Bangya (バンギャ) is a Japanese slang term that is used as label by the hardcore fans of visual kei bands. They are considered groupies who devote their whole life and income to the success of their favorite bands. The term is often used in a negative sense in the media referring to "crazy" women who are obsessed with bandmen to the degree of stalking and murder attempts.
"I really like visual kei, but some of those bangya are really scary so I avoid concerts."