Having given up on life, 15-year-old Chise Hatori sells herself at an underground auction, where she is bought by Elias Ainsworth, a not-quite-human mage, for 5 million pounds. She learns that he intends for her to be his future bride, and her world begins to change.

Long ago, the humans and cats of Ulthar, city of cats, were struck by a great tragedy. For generations, the souls of those who were at the center of this tragedy have been sealed away by the king of cats. Chise and Elias travel to Ulthar in order to complete Simon's second task: to purify the spirits that remain.

To sorcerer Refnred's eyes, Chise is a sad girl, being duped by a mage. But no matter what Elias' true motives are, Chise has no intention of leaving him. Elias was the first person to value her, after all. As she walks towards the epicenter, she learns of the truth behind it. The sight of a boy appears behind the tragedy.

Chise and Elias are in the middle of shearing Wooly Bugs, magical creatures who eat cold from the air and grow wool with magical properties. Chise becomes distracted and is attacked. As Chise recovers, she and Elias open themselves up to each other more.

With Chise being transformed into a fox, she takes off running into the woods. Elias chases after her. Later, Chise is visited by the Leanan sídhe, who is attached to Joel, claiming that Joel will not wake up.

With King Oberon taking Chise into the Fairy realm for recovery, Silke becomes agitated waiting at home. Chise slowly recovers under Dr. Shanon's care, a fairy that was raised as a human.

Christmas is coming up. Alice invites Chise out to London, where they hang out together and go gift shopping for Renfred and Elias.

Stella, a young girl Chise encountered while Christmas shopping, finds that her brother, Ethan, has gone missing and her parents have forgotten he exists.

As the dragon rampages, Elias tells Chise they must absorb the dragon’s magic in order to stop it. This leaves Chise in a predicament as Elias becomes unable to help.

Elias and Chise attend Mariel’s coven meeting and meet Phyllis, Mariel’s high priestess. Secretly, Elias is given information that could help Chise. Following the meeting, Chise becomes suspicious of Elias' activities.

Having captured Chise, Cartaphilus begins grafting parts of her onto himself. He forces her to relive some of her worst memories.

Elias earns the help of many, and they form a search party for Chise. Meanwhile, Chise and Cartaphilus relive his past together.