Potemayo is an odd, yet adorable being that Sunao Moriyama encounters and affectionately names. From then on, Potemayo becomes a constant companion, often perched atop Sunao's head. The discovery causes quite a stir in their school class, attracting ample notice. Later, another creature emerges and is dubbed Guchuko by one of Sunao's peers. However, unlike the amicable Potemayo, Guchuko doesn't display the same friendly demeanor.