Picture book author, Hotaru Yuyami, was heartbroken after losing his beloved dog, Hanako. He was looking at a pink mushroom that had started growing in his yard when it started wriggling and out popped a dog, Mushroom Pup! Mushroom Pup, who loves takoyaki, melon bread, drawing, and Hotaru, is super popular and super adorable. This strange being is sure to heal your heart, too.