Kozue dates many male students in order to keep the attention of her twin brother Miki. Her love for him borders on desperate obsession and is tainted by their troubled past. Mikage and Mamiya decide that the best way to defeat Utena is to create Duelists who have holds on the Student Council members' hearts, enabling them to steal their respective dueling swords from their bodies and use them to fight. Kozue and Miki become the first victims of this experiment.