Originally Posted by
railroadtycoon
I don't think it is expo facto, you should be ok with your ticket. In Japan you don't pay to any official (can't speak for other countries) it is all already included in your ticket fare.
For fares that don't include all the charges, the Check In and Ticketing desks are equipped to take money from passengers for fees. For example, I've paid fees at Check In for last minute award travel when I wasn't able to pay the fees over the phone.