Having experienced working in a traditional japanese company for a year here in Japan, I could truly feel there is discrimination. I can feel a lot of eyes looking at me whatever I do, may it be just standing up just to go to the toilet. I can't even browse the net without the people beside me peering over my monitor. But I have learned to adapt well. I treat them the way they treat me. Since they look at me as a foreigner, I act like one. I don't stay late for work, I go out once the clock strikes 6. And you could say they are plastic, so that's how I act towards them too lol.
(This is only true at work. I have Japanese friends outside of work too)