I love Japanese Culture and all but, I am afraid if I go to Japan for exchange the families will treat me horribly because of my chinese descent please anyone reply...
That's highly unlikely. Families volunteering to host students tend to be more open and accepting of others. And, anyway, blatant discrimination like you are imagining is rare. In Japan it is the systemic (government/legal) discrimination that is the bigger problem. One-on-one, most Japanese are very congenial.