I believe such behaviour is considered appalling in Japan....
Even more than that as have used the Shinkansen on a couple of long trips there with some Japanese friends and watched as some other non Japanese though it was ok even when asked politely by a man to go to end of carraige as there are loads of notices asking people to do that..
Conductor eventually reminded them that 1.) it was against the law and you were required to go to end of carraige 2.) if another passenger complained the train would make an emergency stop and they would be arrested and J-Rail passes would get confiscated and cancelled.
Funnily enough they complied very quickly.
Do love Japan as it is so civilised.