-Saito Kohei is a renowned Marxist scholar from the University of Tokyo
-As a result of ignoring climate change and economic disparity, people are not reproducing anymore
-Japanese social contract has been broken down and lifetime employment has been reduced to irregular employment
-Workers are being seen as nothing more than costs by companies
-Overconcentration of population in Tokyo is happening not due to the wish of the poeple, but due to the concentration of capital there
-Population decline is happening not only in rural areas but in regional cities as well due to this phenomena
-Japan and South Korea are in a grave situation due to advanced capitalism (in their respective countries)
Socialism or Extinction has a good section on it (unfortunately it lacks a table of contents, but its all good).