The difference being the US workers actually work those extra hours. In Japan extra hours are often the result of archaic work culture, for example leaving before your boss (even though you finished your tasks/work for the day) is very frowned upon in most workplaces, so you end up staying longer for no reason. Also, efficiency iis not appreciated. If ia am somehow able to do my tasks for the day in 3 hours and someone stretches that workload to 12 hours, the other guy that stayed longer will be much more appreciated. Since extra hours equals more work done (not) and shows "commitment" to the all powerful and respected company. Like I said a very sick and horrific work culture.