The focus of the movie is on the second installment of Osamu Tezuka's renowned story about a white lion's quest to become the jungle king. When a music box is discovered amid the wreckage of an airplane, Leo's new cub, Lune, becomes captivated by humans. While a covetous treasure hunter named Ham Egg scours for the legendary Moonlight Stones, rumored to be the key to the planet's energy dilemma, two other humans, Dr. Moustache and Lemonade, are determined to thwart his efforts and prevent further destruction of the forest. In due course, a deadly virus breaks out and affects various animals in the woods, but Dr. Moustache arrives with an antidote to save them. The film climaxes with a harrowing journey up the mythical Mt. Moon, in search of the fabled stones.