Japanese keep communication vague in order to maintain harmony. To save face.
Here's an example
"Would you like to come to my party?"
"I'm sorry I have something to do"
Almost nobody will question your something to do.
So both parties are able to save face.
I don't think there is anything unique to the concept other than the whole tatemae "social mask" and honne "true feelings" have been thought about and organized into a system.
200 years of isolation can do that to a culture.