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. However, a group of Mumu's fellow cat-shaped invaders from a radical faction arrives in a spaceship to conquer Earth! Will Sakurako, a regular college student and Mumu's owner, be able to warn her planet about the impending crisis?