I have interviewed many foreign people. Then, I have been hearing their opinions about how they think of Japanese people. Japanese people are thought of as shy, friendly, kind, and polite. They are good points. But there are also bad points such as mysterious because Japanese people tend to hide their real feelings. Therefore foreign people would be confused.
Japanese people don’t express their emotions so much. So, it is hard for foreigners to understand the Japanese people’s feelings. In Japanese society, politeness is one of the most valuable virtues. Therefore, they care about how others think of them. They tend to pretend they are not offensive. For example, when they go to dinner with friends, they wouldn’t say “Ah, it’s boring and I’m tired. I wanna go home.” even if they think so. It is regarded as rude to express their feelings straightly.
If you are not Japanese, it might take time to understand Japanese people. But if you become close friends, they would get to express their emotions gradually.