Planning to work in Japan under the Ssw visa.

I have so many questions that needs to be clarified. Im planning to work in Japan under the SSW visa and im currently studying Nihongo. Does the SSW visa requires me to pass the N4 and N5 JFT exam and become a N4 and N5 passer or being a N5 will do just fine? Second, is the minano Nihongo lessons 1-25 enough to learn and pass N5 and N4? Please and thank you for answering.