GHill18299 wrote:
> [...] Even if you are in Japan on a tourist visa, you might have to leave
> the country to process that work visa (usually in Seoul), which requires more
> money out of your pocket.  Many places are not requiring you to leave Japan,
> but this is only a trend, not something that happens 100% of the time.

Officially, you are 100% *required* to leave Japan to get the Visa.
Even getting it in Korea, and not in your home country is not garanteed.

> Your friends cannot sponsor you unless they can prove they are a school, 

What is exactly needed is a japan established company that does the 
paperwork and engage itsef to immigration to fork out at least 250.000 
Yen/month for the guy.