The story of a white lion cub growing to become the king of the jungle. The movie is an edited version of the 1965 Japanese television series of the same name based on the eponymous 1950s manga. The first 2 minutes of this film are taken from the Jungle Emperor Leo (1965) TV series, while the rest is all original. Tezuka was very pleased that this film conveyed his story accurately, something he wasn't able to do with the TV series.