At the Kyoto stop, I noticed that the man across the aisle dump his backpack in the recently unoccupied seat next to him. Our non-reserved car was nearly full, and the Kyoto boarders were shuffling through, trying to find an empty seat. I wished, not for the first time, that my Japanese was good enough to tell someone off.
Chivalry, sir—learn it.
Shrewdness won the day. An elderly businessman, clearly versed in the trickery of travelers, stopped mid-step in front of the knave, looked up at the empty luggage rack, and down at the offending backpack.
Businessman: <Is anyone sitting there?>
Knave: <Oh. No.>