Paper folding, or origami, is a form of art where you fold a piece of paper (often square and coloured) to form a certain shape, such as an animal, a vehicle, or a plant. As you can guess with the name 'origami', paper folding is majorly practiced in Japan. The word origami is derived from two Japanese words—'ori', which means to fold, and 'kami', which means paper.
In Eastern Asian countries, crane is often portrayed as a mythical creature that brings luck. Such folklore is most prominent in Japan, and the folklore of one thousand paper cranes bringing luck was also derived from the portrayal of crane as a symbol of luck and long-living. The belief that folding one thousand paper cranes will grant your wish became more famous with story of Sadako Sasaki.