Thus you agree with me that integration is huge cost, because immigration will create big friction within the Japanese society and that is a cost.
It is interesting that you admit that Japanese society is anti-immigration and yet you push this as solution to their problem. That is elitism.
> You still also need low skilled immigrants
Another alternative is to increase salaries, but immigration does the opposite, pushes wages down, especially for low income jobs.
Problem is that low income jobs is net loss in payed taxes in high tax welfare states, because the tax they put in is lower that the benefits they get, thus the more low skilled immigrants you bring the higher the taxation must be, but too high taxes will have a negative effect on general employment and business.
Believing that low skilled jobs is something beneficial for an advanced society is like believing that handing out shovels to dig holes is net beneficial in world with excavators.
What a society becomes rich on is processing either goods or services to something of higher value and preferably in multiple steps, not flipping burgers at minimum wage.
You still also need low skilled immigrants. Otherwise, you’re not going to have people do terrible jobs like mortician and meat packer positions to name just a few jobs that native Japanese are hesitant to do. Just to remind everyone, AI and robotics are still not there yet. Anti-immigration advocates, just like the brexiteers, fail to account for reality.