But importing the 3rd world isn't one of them. It's been shown time and again that it doesn't work in any aspect and massively exacerbates the financial issues.

I'm not advocating this solution in particular, but raising the SK corp tax rate to 35% (what the US was prior to Trump), would raise about $11 Billion USD annually just for the top 20 South Korean companies alone. All S.K. corporations would have to be at least double that. Their current social security system is solvent until about 2060. Start adding $22B a year into the system next year, plus increasing the retirement age 2-3 years, plus increasing the individual contribution by 10% and things would likely stabilize within 2 decades.