A group of 245 inhabitants from a planet called Riruru make a crash landing onto Earth from their spaceship.
Aboard the spaceship is a young tiny girl named Memole which the series is centered on.
Here she befriends a human girl named Mariel ("Muriel" in Wee Wendy), who because of her frail health, is forced to stay inside her house all of the time.
After the initial surprise of seeing the little girl Memole, the two become inseparable, and their friendship grows throughout the series.
Memole also meets woodland animals and uses an owl named Bo-bo for transport.