She was the only one who understood the brothers. Whenever their mothers forced them, hurt them, whenever people bullied them since they were homeless, and lived in sewers, she was always their best friend; the cute little girl who was half-cat. Until she became sick, and her family's castle caught on fire, and their best friend disapears. Only for a mysterious girl that looks and acts just like their dead friend, lives with them. What will happen between this new girl? Why is she so dark, and hides so much of what happened in her past life?

Prom is said to be magical, enchanting, amazing, and the time where you dance with the guy of your dreams. It's the time when girls dress up in elegant and sexy gowns, and the boys arrive in style. However, no one knows just how bloody and supernatural prom can get. That is no one except for Yui Komori.