On September 1, 1923, the Great Kanto Earthquake struck the Tokyo-Yokohama metropolitan area with catastrophic force. While the tremor itself unleashed immense structural damage, the subsequent firestorms proved even more destructive. Among the casualties was the Ministry of Finance Printing Bureau in Tokyo.
Within the facility's vaults, officials believed the nation's precious currency master plates, official seals, and specialized paper stock were secure against disaster. However, the raging inferno swept through the district, reaching temperatures exceeding 1,000 degrees Celsius. The intense heat turned the reinforced structures into giant ovens, incinerating paper archives and completely melting the engraved metal master plates used to produce Japanese currency.
With the original master printing plates ruined and the primary printing facility reduced to ashes, the Japanese government faced a sudden monetary emergency. Commerce ground to a halt as undamaged physical cash grew scarce. To prevent economic collapse, the government rushed to produce crude, emergency replacement banknotes.
The situation was so desperate that some of these emergency notes were printed single-sided on low-quality paper, entirely lacking traditional security watermarks or complex intaglio engravings. The loss of the master plates also sparked widespread paranoia about counterfeit notes, forcing the central bank to quickly re-engrave all national currency from scratch. This historic disaster fundamentally altered how central banks handle security printing, inspiring modern decentralized plate vaults and heat-resistant archival storage systems used around the world today.