What is the difference between Kokumin Kenkou Hoken and Shakai Hoken?

Question:

I'm currently working in Japan (just got my work visa last week, hooray). I'm trying to find out about the pros and cons of each insurance system.

Here are some specific questions I have:
1. Does it matter which one I have for the purpose of renewing my visa? Can I get a work visa renewal either way, or is Shakai Hoken required for renewal?
2. If I am covered by KKH, do I still have to pay into the pension system?
3. What are the advantages of Shakai Hoken over KKH?
4. What are the advantages of KKH over Shakai Hoken?

Thanks in advance for any competent, polite answers.

Answer:

1. you'd better ask authority (or a lawyer)
2. I think you can refuse paying pension. In case you're covered by SH, the fee is automatically taken from your salary. (see below)
3. if you get sick quite often, that'll be some advantages.....
4. I think it depends on how much you earn.

- 国民健康保険 kokumin-kenkou-hoken
( for freelance, in case that your company doesn't cover, or for jobless people)
See "Designated Ceilings for Personally-borne medical expenses"
http://en.wikipedia.org/wiki/National_He…
The full English pdf :
http://www.shigakokuho.or.jp/kokuho_sys/…

- 社会保険 Shakai-Hoken：（in case your company pays the fee from your salary that includes "employee's insurance", etc.） http://www.sia.go.jp/e/