"Is Japan a Racist Society?"
Duh.
You can fold it (such as on the topic of where or in which culture you live), and one one side write all the things about it you love. Then, on the other side, all the things you despise.
You can then spend the vast majority of your waking moments enjoying positives, or you can get fixated or obsessed with the other side of the paper and be miserable and criticize the place to death until your last day in country.
It's really anybody's choice.
I've met the happiest foreigners in Japan who made tons of friends and did well financially, and met those who were miserable and could not wait to get home. A number of them walked around with chips on their shoulders trying to change 2000 years of Japanese culture and history. Good luck.
Much of this is a matter of one's own mind.
Maybe it makes Americans and others feel better to tag some other people as racist; and maybe 'they' are or are not. If it makes one feel good to do this, maybe that's fine, too. But the feelings of triumphalism and superiority may not last for long.
Life is a series of cards being dealt to one. How you use the cards is key. I knew people who could make a wonderful experience out of hell, and vice-versa. It's all relative I suppose.