A spaceship from a planet called Riruru makes a crash landing onto Earth. The people of Riruru are cautious about trying to adapt to life on Earth because of their lilliputian size. However, this does not bother Memole. Memole is reckless and brave enough to venture with a group of friends into the city. Here she befriends a human girl named Mariel, who because of her frail health, is forced to stay inside her house all of the time.