So what if he had started raping or murdering people?
Would his victims have been punished as they would have to have acknowledged him?
Good point. Even if he didn't commit any violent crimes like rape and murder, there are any number of ways he could have made himself impossible to ignore.
sharePossibly.
I mean the teenagers who deliberately ran him over seemed to get away with it without punishment, and he was refused medical treatment. It seems that everybody committed to this pretense that he was invisible. Even when he walked into spa and was watching the ladies in the bath, they were uncomfortable doing it, but they were still trying to pretend they didn't see him.
I don't think it was meant to be realistic. More of an extreme way of eradicating somebody being cold or distance. We are to assume that in this parallel world, coldness is deemed the most extreme of crimes.