Nice guy Kio’s normal life gets turned upside down when he meets a friendly, sexy cat-alien named Eris! She’s on a peaceful mission – and she’s ready to play! Things get even friskier when her fellow felines set up base in Kio’s house! It’s not all fun and games, though. Danger is afoot, thanks to several secret agencies and enemy dog-aliens on Eris’s tail!
The story revolves around Kio Kakazu. A girl with cat ears appears before him during a memorial service for one of his family ancestors. The girl calls herself Eris and claims she is an alien. Before long, fanatical alien worshipers and a mysterious government agency are in hot pursuit of Eris, but Kio's childhood friend Manami—who wants to follow in her father's footsteps in the CIA—captures Eris. Kio finds himself having to protect Eris from everyone.