Sushi stories

Tod related these two little tidbits today. He learned them from his colleague, Yoshioka-san.
Sushi has a special counter word for individual pieces: -kan. Most people just use -ko, but really you should ask for i-kan, ni-kan, san-kan pieces of sushi. The kanji for -kan is the same as suranuku, a verb meaning “to pass through.” So why’s that?
Well, 180 years ago, when sushi was new, people carried their money (coins will holes in them) threaded onto a cord. A set of fifty coins was called a “kan” and since sushi was about the same size…
Another sushi tale is why sushi always comes in pairs. Again back in the old days, raw fish for sushi was scarce. So the sushi chefs mounded up the rice really high, put a morsel of fish on top and then sliced the whole thing in two. When food became more abundant, they still prepared two pieces.