From Baka-Tsuki:

"I'm coming to your house to play!" Meet Eris a cosplaying, (or is she?), cutie with neko-mimi that happens to show up at a funeral for a member of Kio Kakazu's family. Enter Kio's Uncle who pushes the two in the right direction…now add the fact that she's not cosplaying, she's actually a cat eared alien being chased by multiple governments and multiple agencies within those governments all wanting her for a different reason, and oh, by the way, she's not the only one coming over to play!

Kio's seemingly normal life with supposedly normal friends turns inside out and as it gets more and more complicated the question is, who's top dog? (er, … um…cat!).