5 Dollars 'Banana Money' Japanese Government

The informal name "banana money" came not from any design element but from the banana tree plantations that the Japanese military promised Malayan and Singaporean civilians as compensation for the scrip's inevitable worthlessness — a promise no one believed. The currency was issued without serial numbers on most denominations, which was a deliberate decision allowing unlimited and untracked overprinting. Inflation followed predictably.

By 1945, a bag of rice cost thousands of dollars in this currency. The collapse was total enough that the British Military Administration, returning after surrender, refused to honor it at any rate of exchange.