Jungle Taitei: Susume Leo!

This story revolves around the grown-up Leo and his family (childhood friend Lyre as his wife, Rune who is the spitting image of Leo, and Rukkio who is the spitting image of Lyre). In the original story, the ending was quite tragic and brought tears to the eyes of the audience, but the ending was altered to a happy one for this animated film. This change emphasizes the "bonds of family."

(Source: tezukaosamu.net)