One thousand origami cranes
The folding of one thousand origami cranes (千羽鶴, senbazuru; lit. 'one thousand cranes') is a Japanese precatory tradition derived from ancient folklore. In Japan, the crane is considered mystical or holy, and historically, paper cranes were offered to shrines and temples by those who sought blessings. The advent of origami allowed the tradition to spread beyond votive offerings to become a broader phenomenon, which grew into the creation of one-thousand origami cranes - one for each year the animal was said to have lived.
In the modern era, the tradition was revived and subsequently popularized by Sadako Sasaki, a child survivor of the atomic bombing of Hiroshima who attempted the senbazuru before dying of leukemia.