Hotaru was a sickly little girl who was possesed by a Tau Ceti entity.Her father and a team of scientists tried an experiment, but something went wrong and it blew up. Everyone was killed except Professor Tomoe. As the professor held his dying daughter in his arms, an entity appeared before him and offered to save his daughter if he agreed to work for them by creating daimon pods.He did and Mistress 9 inhabited Hotaru's body. Sailor Neptune and Sailor Uranus thought they had to kill Hotaru as a part of their mission. Mistress Nine completely took over Hotaru and tricked the Messiah into giving her the Holy Grail. Mistress Nine then brought Master Pharaoh 90 into this dimension. Hotaru became Sailor Saturn then killed Mistress 9 and fought Master Pharaoh 90. Sailor Moon tried to stop her, but Sailor Saturn said only Super Sailor Moon could help her. Now that Sailor Moon had given up the Holy Grail, she couldn't help anyone. Sailor Saturn jumped into a dark pit to fight Master Pharaoh 90. Through a strong display of emotion, Sailor Moon transformed into Super Sailor Moon and jumped into the dark pit to help Sailor Saturn. Everyone thought they were dead, until Sailor Moon reappeared holding baby Hotaru.