Culturally, they are based compared to your average American lefty, but there are still a lot of people that believe the media (fake news) in Japan.

I believe their based-ness is due to their cultures resilience and adaptability towards invaders. I know that's a very "Tim Pool" answer, but consider the fact that they have 3 alphabets:

• One made up of characters for words of Japanese origin.
• One made up of characters for words of foreign origin (same phonetic sound, different characters)
• One made up of Chinese symbols, with different meanings than their language of origin.

So in my opinion, if they lefties tried a full take over on Japan, they are more likely to accept some of it, but never change what makes them Japanese at their core.