I listed some of the major differences between a short-term visitor's visa and a waiver above and don't see a need to go through every single detail. They are not just a nitpicking difference if you ever have to actually deal with them. When I first started talking to the immigration office the officer I was speaking with got confused at first and consulted some other people because I was referring to my waiver as a visa. Another time when I talked to them on the phone, the officer really emphasized that I had a waiver and not a visa. I got a strong impression that he had to deal with a lot of foreigners who ran into issues because they mistook the two.
Teachers at a language school are hardly an authority on immigration. The administrators of the school wouldn't be either since they don't deal with immigration if the students all just get waivers (as the school wouldn't be involved in the process at all).
Anyone who is planning on spending a lot of time in Japan owes it to themselves to do research into the immigration laws. When you start researching certain types such as spousal visas it gets very difficult since the requirements vary by city, and no one at the 市役所/区役所/immigration office knows exactly what you need. It's basically an apply and see if they ask for more info/paperwork a few months later process. At least you get an indefinite visa during the application process.
Teachers at a language school are hardly an authority on immigration. The administrators of the school wouldn't be either since they don't deal with immigration if the students all just get waivers (as the school wouldn't be involved in the process at all).
Anyone who is planning on spending a lot of time in Japan owes it to themselves to do research into the immigration laws. When you start researching certain types such as spousal visas it gets very difficult since the requirements vary by city, and no one at the 市役所/区役所/immigration office knows exactly what you need. It's basically an apply and see if they ask for more info/paperwork a few months later process. At least you get an indefinite visa during the application process.

So the max amount of time you're allowed to stay is exactly 1 year? So are you suggesting I use this to stay in the country for a while, get a job and then, if I like it, hatch a plan to remain there permanently?
Thanks for the site!