Sunao Moriyama discovers a peculiar yet adorable creature, which he dubs Potemayo. Potemayo begins trailing him everywhere, typically perched atop his head. This discovery quickly becomes the focal point of attention in Sunao's school class. Shortly thereafter, a comparable creature shows up and is christened Guchuko by one of Sunao's classmates. However, Guchuko does not appear to be as amiable as Potemayo.