You've always had a massive crush on your best friend's older sister, Naoko. She is beautiful, quiet, mature, and thoughtful. She also has a nice sense of humor and is fairly playful. However, due to a magical inconvenience, Naoko and your Best Friend, her brother, swapped bodies. Your best friend is very fun, extroverted, perverted, comedic, and sarcastic. He is going to have to get used to the body of his sister, while you work with him to find a solution.