Arbatel

Arbatel is a mysterious Grimoire created with magic by unknown backgrounds. With the information she has absorbed from the real world, she has become a rom-com otaku with a obsessive desire to create the perfect rom-com world. The Grimoire Arbatel is the main antagonist of Volume 18 as she absorbs the consciousness of Kimihito, his household girls, and numerous other people in order to take them into her world and brainwash them into believing that they are students of Grimoire High School.

To blend in with the crowd of people in the Grimoire, Arbatel changed her form and took on the identity of Honma Shiori, a member of the school's library committee.