The proportion of households with low incomes in their 40s has increased by 1.5 times in 20 years in Japan, The Ministry of Health, Labor and Welfare summarized.
According to "Welfare labor white paper", the percentage of homes whose head of household is in his/her forties and whose annual income is less than 26,000 US dollars has been increased from 11% (2011) to over 17% (2014). They analyze that this is due to the increment of single parents household and single person household.
On the other hand, over sixty-five years old household The proportion of low-income decreases. The Ministry of Health, Labor and Welfare analyze that the current social security system tends to be more beneficial to older generations than the active generation.
This seems to be becoming a universal problem in other countries. You have to take care of elders, but at the same time, younger generations need some kind of help, too. In Japan, obviously, they fail to have the good balance of Welfare allocation ratio, which results in election results. Younger generation think that government never really care about them so that they stop voting. As a result, politics these days are just supporting elders. Japan is becoming a huge senior care home.
Source:https://headlines.yahoo.co.jp/videonews/ann?a=20171024-00000023-ann-soci
Birth rates are dropping in Japan as well. I've heard that's partially because arranged marriages are no longer the norm.