Subria
what exactly do you mean by coverage? Health Insurance basically covers medical fees by around 80% of the scheduled cost. So if you visit a doctor / dentist you pay a small fee if you have a health insurance card. System is not really designed for use outside of Japan. Pension also is basically designed for domestic use, however their is some facility to withdraw contributions when expats leave the country. Not really sure about the details about how much can be withdrawn or tax implications.