PROLOGUE This is about a young girl who fell from the sky, glowing as bright as a star. Japanese scientists took her in their custody and researched about her. They learned that this girl possesses incredible powers, and they couldn't find out if this girl was human or not. Reiko Jou-sama, the head scientist, had the idea of making the girl live like a normal high-school girl to learn if she's truly human. He assigned his eldest daughter, Nanami, to be with the young girl during school. While he asked his second daughter, Ayumi, to be her fake sister, to watch her movements at home. To do this without a hitch, they drugged the young lady to forget about her past life so far and named her Akemi. They gave her a new set of memories and because of this, she now lives as a second year high-school student named Kou Akemi.