I visited Japan a couple months ago during "Golden Week", which is their big national vacation week. Several of the sites I visited were absolutely packed with (Japanese) tourists. No one was vandalizing anything, littering, or even acting rude and obnoxious, or in any way I could see breaking any of the rules. As an American, it was rather weird because American tourists wouldn't be like this at all. It's pretty amazing to see a culture where people know how to act properly even when there's a high degree of crowding.