Kei Satou is a lonely corporate slave with poor communication skills who applies to live in a share house hoping to make friends. He soon discovers that the three other occupants are not ordinary people. Chiyuki Himiyama is a snow woman with a tsundere personality, Meme Janome is a Medusa with a boyish yet gorgeous appearance, and Yume Incuria is a surprisingly cute incubus. This residence is actually a special share house for demi-humans, which ordinary humans are not supposed to know about. Despite his initial shock, Kei decides to stay and live alongside these supernatural beings.

The story follows the daily complications and growing bonds between Kei and his monstrous housemates. Himiyama struggles to learn trust, Janome works to connect with others without fear, and Yume faces prejudices about being an incubus. Kei must overcome his introversion to forge friendships with them. As the series progresses, the forced cohabitation transforms into a genuine community of mutual support, with heartfelt conversations and small gestures of affection allowing a beautiful friendship to blossom. A romantic relationship eventually develops organically between Kei and Yume.

The narrative includes several comedic and unusual arcs as Kei adjusts to life with demi-humans. He experiences being turned into a girl, gets chased around by maids, and helps Janome shed her skin like a snake. Over the course of the 21-chapter, two-volume series, the distance between Kei and his housemates slowly closes as he works to find the warm, happy life he has always dreamed of.