The big Japanese corporations are desperate to bring in more people as the work force dries up and there's literally not enough construction workers or truck drivers or food service workers to keep things going. The politicians and their conservative voters are desperate to keep people out because of their xenophobia.

What you end up with are people brought over from places like Vietnam on "apprenticeships" put into overcrowded dorms, paid peanuts (even by Japanese standards) and then sent home as soon as their limited term in Japan ends with no pathway to residency.

Then, predictably, those exploited migrants need to work on the side or steal just to survive and all the conservatives point and squeel about how foreigners can't fit into Japanese society.