Where are you seeing that there is a labor surplus in Japan in recent years?
https://www.npr.org/2018/12/07/674548447/facing-critical-lab...
https://www.reuters.com/article/us-japan-economy-workculture...
> As of 2019 Japan's unemployment rate was the lowest in the G7.
> Japan is now facing a shortage of labor caused by two major demographic problems: shrinking population because of a low fertility rate, which was 1.4 per woman in 2009, and replacement of the postwar generation which is the biggest population range who are now around retirement age.