She was originally Countess Rose, a teacher at a finishing school, but was turned into a monster by Malachite, who suspected that Sailor Moon might enter it. She trapped Lita and Amy, along with all the other girls (except Serena, Raye, and Mina), in wax. Serena, Raye, and Mina transformed while Luna and Artemis attacked Polite Society. As she was fighting them, Prince Darien, under the control of the Negaverse, arrived and told her not to kill Sailor Moon, as their mission is more to get the crystal. However, Malachite wanted her to kill Sailor Moon. Eventually Sailor Moon healed her with Moon Healing Activation.
Her Japanese name Shakokai (シャコウカイ) is a combination of the Japanese word "Shakou" (社交) meaning "Sociability", and "Kai" (貝) meaning "Shell".