I was watching the last couple of episodes, and something struck me... that very special sake that Inokuma-sensei drinks, the jigokuruma one - which you very aptly translate as "Hell on Wheels Sake" - is that a real sake brand? Or is it a parody of a known brand?
I ask because, though I do speak Japanese and enjoy sake, I am fairly ignorant of the finer details of brands, etc.