i know somebody in /k finish N2 by minna no nihongo 1-1 oni without class, but he have an extensive exposure of "Japanese media contents" for a few years...

msia version didnt mentioned 初級 or 中級... it was go by beginner *1-1 and 1-2) or intermediate (2-1 and 2-2)...

my point is if you only going to relied on academic way to learn japanese by going class, tuition or study material to master this language, it going to be a very long way because what u learnt may only limited to the standard and polite japanese (we called it 標準敬語 (ひょうじゅんけいご)), which is fine until you planned to work in japan or japanese reliant job...

the japanese language used by japanese during normal circumstance is so different to a point where you could get discriminated by staying with those standard way of speaking where they find it too rigid and serious