I'm betting it has to do with the Lewis Hamilton impersonation.
Do the rotors get red hot when you hit the brakes?
And if you really are a Japanese woman that knows about Hamilton and looks anything at all like this
BTW, what car is it? Some are more notorious from brake dust than others and can usually be remedied by changing to a different type of pad. Also, get some Dupont Teflon car wax and spread it liberally on the wheels. It will help keep the dust from sticking.