Sunao Moriyama finds a strange but cute creature in his refrigerator that he names Potemayo. Potemayo starts following him everywhere, usually riding on top of his head. His discovery becomes the center of attention in his class at school. Soon after, a similar creature appears, and is named Guchuko by one of Sunao's classmates. However, Guchuko doesn't seem to be as good-natured as Potemayo.
Sunao Moriyama is a junior high school student living life with (and without) his constantly-traveling father. Things change when he encounters a strange, childish creature that came from his refrigerator. With the help of his newfound friend, Potemayo, Sunao learns that life is about more than just school.