Another example of this experimentation is Isao Takahata's 1974 television series "Heidi, Girl of the Alps". This show was originally a hard sell because it was a simple realistic drama aimed at children, and most TV networks thought children needed something more fantastic to draw them in. "Heidi" was an international success, popular in many European countries, and so successful in Japan that it allowed for Hayao Miyazaki and Takahata to start a series of literary-based anime ("World Masterpiece Theater"). Miyazaki and Takahata left Nippon Animation in the late 1970s. Two of Miyazaki's critically acclaimed productions during the 1970s were "Future Boy Conan" (1978) and "Lupin III: The Castle of Cagliostro" (1979).