The population was projected to decrease after 2010.
Explanation:
Japan is one of the few countries in the world in which the population does not grow, but decreases year after year. This is due to a multiplicity of factors, the most important being the low birth rate and the lack of large migratory flows to the country.
Thus, as of 2010, the Japanese population began to fall numerically: from its historical peak in that year of 128 million inhabitants, to the year 2021 its population has fallen to 126 million inhabitants.
