One day, the typical Sunao Moriyama found something not-so-typical in his refrigerator: a small creature between the potatoes and mayonnaise that he dubs Potemayo! Sunao decides to take care of Potemayo and takes her with him everywhere he goes, and as a result Potemayo quickly becomes popular with Sunao’s classmates. However, the tranquility of the new friendship is broken with the arrival of another creature from Sunao’s fridge – this time a scythe-wielding laser-shooting horned creature he dubs Guchuko. Now, every day brings new adventures and surprises with Potemayo and Guchuko around!