Kio is just another boring, nice guy with a boring, nice life until he meets a beautiful, curvaceous cat-girl while attending a memorial service for one of his ancestors. Next thing he knows, he's lying in bed with this half-naked beauty next to him! Her name is Eris, and she has come to Earth to learn more about its inhabitants as a representative of the planet Catian. And she's decided to set up shop at Kio's home for her stay on Earth!