In 1988, Studio Ghibli released My Neighbor Totoro and Grave of the Fireflies as a double feature. The Hayao Miyazaki film follows the adventures of two sisters with a mysterious fuzzy friend, while Isao Takahata’s film dealt with two siblings experiencing the horrors of war.
Source: Kotaku – The Surprising Similarities Between My Neighbor Totoro And Grave of the Fireflies