In this world, in addition to humans and monsters, there is another species - the reverted monsters produced by the combination of humans and monsters. Due to their impure bloodline, reverted monsters are often expelled or even hunted by their own kind. Therefore, a "monster house" that provides shelter for reverted monsters came into being. In the monster house, each reverted monster is equipped with a guard called SS, and the story of Shirakariin Rinrincho (voiced by Hidaka Rina) and Mikoshin Sochi (voiced by Nakamura Yuichi) begins. In the monster house, there are other interesting residents. The leisurely but unexpectedly delicate character of the Fushinozuka Rensho (voiced by Hosoya Yoshimasa) and his guard Yukikoji Nobara (voiced by Hikasa Yoko); the bad boy Watari Manri (voiced by Eguchi Takuya) and his guard Natsume Zanxia (voiced by Miyano Mamoru); the unruly and even perverted Aokiin Qinglong (voiced by Sugita Tomokazu) and his unlucky guard Gorokumiya Karuta (voiced by Hanazawa Kana). In the process of getting along with these monsters, Linlindie regained the long-lost happiness. At the same time, the lost memories of the atavistic monsters gradually surfaced.