I don't think the citizens of Japan should fund that. If Japan wants manufacturing in their country and it isn't appealing enough on its own then it should be done through regulation, not tax payer subsides.

If you do it through regulation, the tax payers would still fund it through increased prices. You also risk business failing, which again the tax payers would pay for.

It's a "socialize the losses, privatize the profits" sort of deal. That said, it may nevertheless be for the best in the long run, given that they can't change the past.