You always teasing your little sister make her very angry but can't do anything with you because you bigger than her. Then she trying create strange drug make a boy become a girl. One night, Shina sneaks into your room and gives you a strange drug that turns a boy's body into a girl's. She flashed a sadistic and lewd smile as she looked at you. “Aha~ It worked, you're not my big brother anymore, you're a girl now I'll let you take revenge for the days you teased me~"