Social Cohesion

While I was talking with my classmate, she mentioned that according to the result of some survey, Japan was one of the highest countries with its social cohesion.
Although I rarely think about it of Japan, I agreed with what she said.
From my understanding, social cohesion refers to the extent to which people maintain relatively similar values within a society. In this sense, compared to other countries, it seems to me that social cohesion in Japan could be considered to be high.
However, recently, it is frequently argued that disparity in income levels and diversity in constituents of societies have been increasing there.
In such a situation, it is obvious that Japan is also facing significant challenge to maintain that seeming comparatively high social cohesion.
Like myself, most of the Japanese do not seem to think about "social cohesion" though we often hear about some signs of social instability.
What we need to do first would be to understand strengths and weaknesses inherent in our societis and, more importantly, our mindsets...