Xiuyi (voiced by Daisuke Ono) was born into a noble family. His grandfather was a book collector who was keen on collecting all kinds of precious books. After his death in an accident, he left behind an old manor and a house full of books. His grandfather's will stated that if he wanted to inherit his mansion, the condition was to inherit Danterian's bookshelf. After receiving the letter, Xiuyi visited the mansion and met a mysterious girl, Dallion (voiced by Miyuki Sawashiro) in the pile of books in the basement. Because of investigating the cause of his grandfather's death, Xiuyi came to Conrad's mansion and saw the terrible scene caused by the phantom book. "Phantom book" is a dream book that should not exist. It contains a powerful forbidden power that can grant readers endless benefits, but it can also subvert the world and cause it to collapse. The seal of the phantom book is Danterian's bookshelf. Dallion ordered Xiuyi to take out the key and recite the spell. The huge lock on her chest flashed with a metallic luster. It turned out that the girl Dallion was the entrance to Danterian's bookshelf... This animation is adapted from the light novel of the same name by the writer Mikumo Yuedou.