Even under the "repeated ravages" of washing machines and dryers, people are as stiff as nothing after taking them out and drying them. Behind this stunt, yen paper money is a general term for paper made of traditional paper and traditional Japanese technology, which has a history of 1300 years.

Not only that, it has been found that even crumpled old paper money can be turned into new paper money as long as it is slightly wetted with radish mud juice and ironed at low temperature.