A famous story about senbazuru is that of Sadako Sasaki (see”Sadako and the Thousand Paper Cranes” by Eleanor Coerr ).
Sadako was little girl who ws exposed to radiation as an infant when the atomic bomb was dropped on Hiroshima. Although she survived the bomb, she was diagnosed with leukemia by the age of 12.
She decided to fold 1000 cranes, hoping that her wish to live would come true. Unfortunately, she only was able to fold 644 cranes before she passed away. Her classmates then continued to fold cranes in her honour and she was buried with a wreath of 1000 cranes to honour her dream.
There is now a statue of Sadako in Hiroshima Peace Park – a little girl standing with her hand outstretched, holding a paper crane. Every year, thousands of wreaths of senbazuru are draped over her statue.
Article from Meaning of The Origami Crane