Sunao Moriyama discovers a peculiar yet adorable creature, which he names Potemayo. Potemayo begins to follow him everywhere, typically perched on top of his head. This discovery draws the attention of his classmates at school. Shortly thereafter, a similar creature appears and is named Guchuko by one of Sunao's classmates. However, Guchuko does not appear to be as good-natured as Potemayo.