Marvelous Melmo (ふしぎなメルモ, Fushigi na Merumo) is a magical girl manga and anime by Osamu Tezuka. This series centered on Melmo, a nine-year-old girl whose mother is killed in an auto accident and has to then take care of her two younger brothers (Totoo and Touch). While in Heaven, the children's mother is given one wish. Her wish is that Melmo (the oldest out of her 3 children) will be allowed to grow up more quickly than usual, since their lives as children will be difficult without their parents.

Melmo's mother is permitted to visit her as a ghost, and gives Melmo a bottle of candy given to her by God. The blue candy turns Melmo into a lovely 19-year-old version of herself, while the red candy turns her back into a child. Combining the two turns her first into a fetus, then into an animal of her choosing. When Melmo ages from 9 to 19 her clothes don't grow with her, usually resulting either in shredded clothes, or skin-tight children's clothes on the body of an adult woman, leaving little to the imagination (for this reason the series was one of the first to make regular use of the now-common panchira, or "panty shot"). This was only the case of the anime; the manga had Melmo's clothes change with her into whatever she desired (ranging from a police uniform to a fairy costume). A total of 26 animated episodes were produced, which aired from 1971 to 1972.

Although most of the episodes of the anime revolve around adventure stories, Tezuka intended the series to also function as a kind of introductory sex education for children and Darwinist evolution. That being the case, not surprisingly the series only aired in Japan and Italy (as I bon bon magici di Lilly, lit. Lilly's magic bon bons). When the manga first appeared in 1970, it was originally titled Mamaa-chan. However, by the time the anime debuted in 1971, the name of the main character was changed to "Melmo" (derived from "metamorphose") due to "Mamaa" having been previously trademarked. Many Japanese parents reportedly hated the show, since it raised many questions from children that parents were uncomfortable with answering.