Metamorph Meena

In "Metamorph Meena" the player controls Mai, a little girl who has a crush on an older boy who, naturally, doesn't pay any attention to her. But one day she meets two imp-like creatures, one of whom is Pal, the 153rd prince of a magical world called Dream Star, and the other his court magician Pul. The two turn Mai into an adult young woman, and she begins to explore her newly found sexuality...

[From Moby Games]