They're not guards, either. Their official job title is "pusher", and that'* the entirety of their job. I mean, sure, they help people figure out their tickets, and give directions and such, but shoving people into trains is their primary duty...I could get used to a job like that! I mean, over here the worst you can do is be figuratively "pushy" towards people. I'd love to have a job where I get to actually physically push people around all day!
BTW, is it any wonder, looking at that, that the fastest growing crime in Japan is sexual assault on trains? Can you imagine trying to figure out who just put their hand up whose skirt?