Kōtarō Satomi decided to live on his own when he began high school, and chose Room 106 of Corona House because it was cheap. Unfortunately, Kōtarō soon discovers that numerous otherworldly and supernatural girls also want his room for various reasons of their own, and aren't about to back down. As a result, Kōtarō and the girls find themselves forced to live together as they try to settle just who ends up with the room.

Rokujyoma no Shinryakusha!? (六畳間の侵略者!?, lit. Invaders of the Six-Tatami Mat Room!?) is a Japanese light novel series written by Takehaya and illustrated by Poco. HJ Bunko has published sixteen volumes since 2009 under their HJ Bunko imprint, as well as two side story volumes. A manga adaptation with art by Tomosane Ariike is serialized in Hobby Japan's online seinen manga magazine Comic Dangan. An anime television series adaptation by Silver Link airs from July 2014.