I have a 3 year visa and a multiple entry re-entry permit valid until the end of my visa. I think that's the max it can get. I am not sure though..
yeah permanent residency have to be applied.
5 years? Is it only applicable for those married to Japanese nationals? Cause I know some people who are single and they were required to live here for at least 10years. One was even denied and the reason was he did not reach 10years yet.
After about 8 months I guess, he re-applied and was granted.