 The film was a large scale major project, involving a total of 13,590 staff; surprisingly, it only took eight months to finish.And while the film received honors at the Venice Children's Film Festival in Italy in 1959, it was regarded as a disappointment when released to the United States on March 15, 1961 by Global Pictures.Historically, this film marked Tōei Dōga's first attempt to follow the example of American feature animation studios and become the so-called "Disney of the east."