How to get health insurance as a student (not affiliated with college)

I'm an older American interested in taking off a year to do language school in Japan. I have enough savings to last me about a year.

However, is health insurance something I need to worry about? Here in America if I happen to get a heart attack or into some accident I'm screwed. Is it feasible to go without and just pay out of pocket even if its something that requires a hospital stay (or god forbid surgery)?

I'm fairly healthy but getting up there in years, so I never know what may happen.