At the age of twelve, a Japanese girl living in Hiroshima, Sadako Sasaki fell ill from Leukaemia.  Sadako had been a baby when the bomb had dropped but lived within two kilometres of where the bomb exploded. The disease was attributed to the side effects of the atomic bomb.

A visitor to her in Hospital told Sadako of a legend.  She told her that if a sick person folded 1,000 paper cranes they would soon get well.  The crane was a sacred bird in Japan that lives for a hundred years. Determined to beat her illness Sadako set about folding 1,000 cranes.  She kept folding throughout her illness but sadly died before completing the task.  She had managed to make 644 paper cranes.

Word of Sadako’s efforts spread quickly throughout Japan and overseas, and money was collected to build a monument to her memory.  On May 5, 1958, almost 3 years after Sadako died, a monument to her was constructed close to the centre of the Hiroshima Peace Park.  It is now known as the Children's Peace Monument.

People from all over the world continue to send folded paper cranes in memory of Sadako Sasaki.  On August 6, world peace day, a ceremony is held in her memory where the cranes are placed on the monument.

Folding 1000 cranes continues to be associated with Hiroshima and other peace movements who use origami cranes as a method of showing their commitment to world peace.