Melmo's First Love
The man who helped Melmo when she was being picked on by a student gang on her way to school turns out to be Mr. Nozawa, a new teacher. Melmo instantly falls in love with him. She even dreams about getting married to him. Melmo takes candies to grow up, introduces herself to Mr. Nozawa as Melmo's elder sister, and asks him out. But on the first date, Mr. Nozawa tells her that he will be getting married soon. On the next day, the broken-hearted Melmo leaves school early. Source: tezukaosamu.net
Aired 06/02/1972EP 19 - Melmo's First Love

Fushigi na Melmo
After nine-year-old Melmo loses her mother in a car accident, she is left to care for her two younger brothers, a task far beyond her age or means. However, in the midst of her grieving, Melmo is visited by the ghost of her deceased mother who gives her a bottle of miraculous candy, capable of transforming her into either an adult (blue candy) or an infant (red candy). A combination of the two can reduce her to a fetus and then change her into any animal she imagines. Drawing on a seemingly inexhaustable supply, Melmo uses her candies to solve the various problems thrown her way, aided by her younger brother Toto (who accidentally morphs into a frog in episode 7) and her cantankerous mentor, Dr Nosehairs.
(Source: Anime News Network)