In addition to keys and eyeglasses and other commonly lost objects, millions of dollars worth of cash reaches the Tokyo police's lost and found department every year.

In fact, last year people handed over a record ¥3.67 billion ($32 million) in lost cash, and about three-quarters of that money ended up back with its rightful owners, according to the Metropolitan Police Department.

It's a phenomenon that reflects the Japanese people's devotion both to cash and to returning lost property.