I would love to hear more about your experience, Anna! 

Thinking about that situation, I myself have told people around me that "I don't really like them, I think their voice is annoying"  but no one really minded and we kept talking about the subject. Sometimes when one of my close friends is excited about something I don't even care about, I'd let them know I'm not interested but keep asking stuff about it just so I could see them being cute and so they'd have someone to talk to. And then if they call me to something more compromising (like a show or anything too far or expensive) I'd say "I don't really mind talking to you about that, but I'm not willing to put that much effort".

It really seems natural for us to just speak what's in our mind, but I can also remember plenty of situations that didn't go well because of it.

I think that may be why I come across as rude in the internet so often HAHAHAHA

Thank you so much for your answer, it gave me a lot to think about!   ^-^

Thank you so much for the book recommendations, I'm gonna look them up! 

That example you gave really sounds awful, but I still think it'd be awesome to actually understand what's going on in the room by people's behavior and from that know the best action to take. 
I think it's awesome to protect someone's feeling, but Japanese seems to take it too far, in my country we would call that being a "fake person" and wouldn't trust them at all. 
What I'm trying to say is that it's actually an awesome skill, to be able to understand what people are not telling, specially when people don't know how to express themselves.
I think maybe using this in your life full time might be exhausting and a bad idea, but the total lack of it is also bad. 

I learned a lot of awesome things from Japanese culture and behavior, but I don't plan to act like them, I just want to add what I think of as useful and improve myself. I am still myself after all. 

Thank you so much for your answer, that was really useful!