My department is about 25% foreigners and some of us have been there for over a decade, they need our foreign language skills. The last chief was a German and before that was an Australian so we do get promoted (unless you’re Asian). On the company level you are treated based on your job performance but I’m not going to lie and tell you that your metrics for evaluation is the same. They expect you to perform on a lesser level than Japanese employees and they’re pleasantly surprised when you do well. Which pisses me off. Socially they treat you as a curiosity and it’s super hard to make friends but once you make them you’ll have them for life. Also if you try to speak to them in Japanese they look at you like you’re some sort of talking dog lol.