tsukishiro yuki

The former classmate of Sakuraba Ema and Nikaido Hiro thought to be dead. She is revealed to be the last surviving "Great Witch" and the true mastermind behind the prison that the girls are trapped in.

Before she met Ema and Hiro while disguised as a human, she took in Hikami Meruru during her time as a witch, and considered her as family.

She has white hair and white eyes, and usually dresses in a white lolita dress.