Earlier quoted context omitted.
You raise a good point here. There's a degree of trust here, too. Trust placed on the consumer to do the right thing and pay. I'd also say there's an additional consideration being put forward by the operator: sometimes people just need a ride every now and then. I've been Japan three times now and I've seen several incidents of the guards letting people just walk through without a ticket because they explained some…
I've went through gates without ticket several times for reasons like access to coin lockers or switching to the other track when I've entered the wrong one. Gate guards usually hand you a slip that explains the situation at the other gate or when leaving again.
For example: You'd explain to the staff that you want to use the toilets, and they'll hand you a plastic NFC token coin, limited to enter and exit at the same station. You use that to enter the paid area, go to the toilet, then deposit the coin in a special slot to exit.
>Gate guards usually hand you a slip that explains the situation at the other gate or when leaving again.
That was done in the past, but it's quite nice that they just hand you a token now.
Alternatively, train stations in the Netherlands have done away with fees for entering and exiting the same station altogether. Toilets within stations often charge a €0,70 fee, though.