Every so often there's a big news story about someone finding a huge amount of money in the unlikeliest of places. The most recent one had to do with tens of millions of yen in cash discovered in a stream in Hasuda, Saitama Prefecture.
Later, it was revealed that the money was actually stolen and abandoned. A woman and some accomplices broke into the residence of the woman's ex-boyfriend. She knew that he kept all his money at home, but after lifting the loot she got scared and threw it away.
Though other stories about found money usually don't involve larceny, they all point to a trend: people hoarding lots of cash. In many cases they're old people who just die and their relatives, unaware that there's money hidden in that old kimono or at the bottom of that chest of drawers, throw their possessions away. Later some lucky sanitation worker finds it.