Is Japanese people Shy?

Yes, Overall average national characters of Japanese is Shy;

Fundamental education: Try not to bother someone, Drama-Free.

For this fundamental education, sometime, Yes they are Shy people.

Some people say Japanese has two faces. Be seemingly being nice but are thinking of different things. 
Yes, it is also right compared. So some time travelers might be confused and misunderstand. But it is not only Japanese, it would be a feature of the human race. 

Definitely Japanese are polite and kind at a first contact and they will try to help you when you ask even they could not speak English well. Don't you think it is better than not a kindness?

So please ask any question to Japanese, you do not feed bad normally.