The communicative, corporate animal Kei Sato applies to move into a shared house to make friends with whom he can have casual conversations. The three people there were Chiyuki Himiiyama (Snow Woman), Meme Janome (Medusa) and Melodrama Incuria (Incubus).
This was a shared house exclusively for subhumans, who were supposed to be invisible to humans. The shared house life begins with a lot of difficulties ahead.