On her 16th birthday, Himari Momochi receives a letter stating she has inherited a mansion called the "Momochi House." Having been raised in an orphanage, this mansion is the only thing left of her real family, so Himari pays no mind to the rumors that it may be haunted. Upon entering it, she meets Aoi Nanamori and his companions, Ise and Yukari, who all seem to be squatting in her new home. Although they warn her to leave the house, Himari vows to be the one to make them leave instead. But soon, she is attacked by youkai and finds out that the house sits in the space between the world of the living and the spirit realm. Even more surprising, Aoi was chosen to be the guardian of the house—a position originally meant for Himari. But this great power came with an awful price: Aoi can never leave the mansion, and his existence in the human world has been erased. Ignoring his pleas for her to leave the mansion, Himari promises to help Aoi break the housebound curse as she begins living under the same roof as him.

The player Dongdong mistakenly entered the game world "Azure" and changed into the skeleton, the weakest wild creature. The unidentified Dongdong used his years of gaming experience to amass a band of wild monsters early on. He met the main character Bubble, made a deal with her to become her strongest pet, and then set off on an amusing and thrilling adventure with Bubble and his new pals in "Azure." The phenomenon of NPCs and wild monsters in the game gradually awakening and yearning for the human world was also identified at this time by Dongdong. To learn the truth and get back to your regular life. The main character group, lead by Dongdong, as well as awakened NPCs, regular players, game developers, and other entities started to debate how the two worlds were connected.

The Demon Lord Tasogare's castle is a dark and frightening place, filled to the brim with various monsters. Any soul unfortunate enough to be imprisoned here is sure to be terrified by the horrors within. However, the human princess Aurora Suya Rhys "Syalis" Kaymin is a different case. Rather indifferent to her situation, Syalis worries about one thing and one thing only—sleep. Ever since the demon lord kidnapped her from her kingdom, she has not had a single good night's rest. To alleviate her dozen dozing issues, the princess makes do with what she can find in the castle. Whether it be the fur of fluffy demonic teddy bears or the silky, blanket-like bodies of ghost shrouds, everything is but a means to ensure a peaceful slumber. With so many potential materials to craft items that can help her sleep at her disposal, nothing will stop the sleepy princess—not even death. [Written by MAL Rewrite]