Facing extinction, an alien race travels to Earth and decides to blend in amongst the population to rediscover the technological secrets it has lost. After scanning the planet's inhabitants and declaring it's rulers to be cats, they descend upon the planet... Mumu, one such invader finds himself in the home of Sakurako Umeyashiki, a freshman university student who's a bit of shut in. Together, the two become proud members of the Human Regeneration Study Group in order to understand technology...