The film is based on the eponymous book. However, the claim in the book that Sadako "died before completing the 1000 cranes, and her two friends completed the task, placing the finished cranes in her casket" is not backed up by her surviving family members.
In his book, "The Complete Story of Sadako Sasaki", her older brother Masahiro Sasaki, says Sadako exceeded her goal of 1,000 and died having folded approximately 1,400 paper cranes.
In his book, "The Complete Story of Sadako Sasaki", her older brother Masahiro Sasaki, says Sadako exceeded her goal of 1,000 and died having folded approximately 1,400 paper cranes.