Planet Earth has been invaded! By a cat-shaped alien obsessed with...appliances, no less. An alien named Mumu is a survivor of a civil war that saw the destruction of his planet's scientists, leaving only its fools alive. In an attempt to understand the advanced technology his species left behind, he's infiltrated Earth, a planet with a lower level of civilization, to study their so-called "home appliances," which contain facets of all kinds of technological knowledge. So begins the adventures of Sakurako, a university freshman and Mumu's new and unexpected accomplice, as she navigates a wild and exciting campus life.