The 1 yen coin can be used as a weight, because it weighs exactly one gram. Also, it can float on water.
19
In Japan, watermelons are grown into the shape of a square so they are easier to stack and transport.
108
In Japan, it is tradition for husbands to get a monthly allowance from their wives.
6
Japan's capital Tokyo means "Eastern Capital".
1
The Japanese, on average, are the shortest people.
320