See https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1... , especially paragraph #332.
I don't mean to say that this is a coincidence as far as the European languages go; negation words with N are often a shared inheritance from Indo-European
https://en.wiktionary.org/wiki/Reconstruction:Proto-Indo-Eur...
Makes total sense now.
I think there's an innate human desire to modify the sentence to make it a question with as few additional sounds as possible.
On va prendre de l'essence d'abord, nan?
We're going to get gas first, right?
Swedish:"må" <=> Japanese:"mo". "allowed to" Pronounced the same.
Expression: Swedish:"det går inte"(not possible, not allowed to), literally "that does not go" <=> Japanese:"ikemasen"(not allowed to), literally "can not go".