There's definitely discrimination. Probably more discrimination than white gaijin, since the japs like western culture, etc.
Japs don't like other asian countries mainly cause they think they're better than the rest. I don't think being chinese is too bad. There's a greater resentment for koreans.
Even if they have this sort of thinking, by default every jap is overly polite upon first impression. Even if they're fake, I don't think you would receive any direct discrimination.