The last 2 panels are an injoke – a reference to some of Futaro Yamada’s writings (not translated into English of course) – this is the sort of story where, I think, heavy localisation would go against the whole point of the thing so unfortunately there’ll be a lot of references like this that an English speaking audience won’t get (c.f. the “death by poo” (unko satsujin) comment early in chapter 1)