What is bred in the bone will not out of the flesh. (背に腹は替えられない。 Se ni hara wa kae rarenai): is the 40th chapter of the manga written by Kore Yamazaki.
After Isaac comes before Phyllis to talk about Mariel, Ethan discovers that Stella isn't home. Chise finds Elias carrying her but he attempts to knock her out with a spell before she can find out why. Ruth and Elias leaves her to start the ritual but she recovers shortly afterward and proceeds to follow them. Cartaphilus reveals himself to Elias before Chise enters the room after an encounter with Silky. Cartaphilus tricks Chise and she gets frustrated at Elias for his actions and reasons behind it. She calls him a monster and leaves with the help of the Jade Ariel.
Once outside, Chise discovers that Stella is in fact Cartaphilus. He wants to make a bargain with her in order to save Stella and a spell that could help her with the Curse. Elias and Ruth catch up to them but Chise makes up her mind and leaves with Cartaphilus.