Honor student Shiizaki Lulu happens to see Katya and Hana together in the preparation room of the science lab. She is found out and caught, and Katya moves in close to her before abruptly holding back. Not long afterward, Lulu goes with her mother to a strange ritual held by a shadowy cult. This single-episode OVA mixes action, ecchi and supernatural elements. It adapts chapter 16 of the manga, which centers on Ekaterina Kurae, fits in as episode 10.5 of the anime, and came packaged with the tenth manga volume.