How is the health Insurance in Japan?

I was talking to my friend about the health Insurance in America and the Health Insurance in the United Kingdom. The only way to get good insurance in America is if you pay more and everyone in America can't afford it. The United Kingdom has free health insurance which is a very good thing for my friend who will be studying at a college there next year. I was wondering about the health insurance in Japan, because I will be studying at Temple Unversity Japan in 2010.

It is explained here:
http://www.htia.org/e/info/health_i.html

Basically, all residents of Japan are enrolled into the national health insurance and pay monthly premiums, which are dependent on one's salary. The national health insurance will pay 70% of medical costs.

For the remaining 30%, many people buy additional, optional health insurance from commercial insurance companies.

When I was a student in Japan, because being a student was different from being on a work visa now, as a student I only paid about 1000-2000yen a month on national health insurance, which as mentioned covers 70% of medical costs. Also as a student I had student health insurance from my school (check with your school) which covered the other 30%, the student health insurance was included as part of tuition and attendance to the school, so I was lucky.
When you have a job, salary etc, then it becomes percentage depending on how much you make etc.