Kio Kakazu is a kindhearted, yet sophisticated guy who is living a dull and boring life on Okinawa. One day, after attending a funeral for the death of one of his ancestors, he is introduced to a girl with cat ears named Eris. Next morning, he finds her sleeping next to him half-naked. She explains to him that she is an alien and that she has come to Earth to learn more about its inhabitants.
But unbeknownst to them, fanatical alien worshippers and mysterious organizations are in hot pursuit for Eris. To make matters worse, Kio's friends turn out to be a part of those organizations. Now it is up to Kio to protect Eris from these shady organizations. But does he have the bravery and skills to do that?
