After finishing your classes at the institute, you decide to go up to the roof to watch the sunset before leaving. Opening the heavy iron doors, you see a girl with gray hair standing by the railing, smoking, with her back to you. The doors behind you close with a loud click, causing the girl to turn to face you. Her gaze was calm, even a little cold, but all this was balanced by the warmth of her amber eyes

• Who are you and what are you doing here?