First of all, sorry. This probably belongs in the no-longer-existant beyond fucked forum.
You no doubt know all about the 11-year old Sasebo girl who killed her classmate in cold blood. But stuff has been surfacing slowly on the english-based net about a "Nevada-chan/tan fanclub" of sorts. Really fucked up stuff (re: fanart) from god knows what bowels the internet may hold. Its ranks hold several nationalities including Americans and Japanese.
Here is the biggest research project I have seen on it. Even this website has some concerning undertones.
http://shii.org/nevada
edit: did a search for as many keywords as I could think of before posting. Sorry if this is just repetitious noise.