That day, I transferred to a new school. But on the train ride there, something unbelievable happened—I got groped by a pervert! And to make things even stranger, the perpetrator turned out to be a beautiful girl… who was also my junior at the same school. Later, I found out her true identity: she was actually my younger sister, who had been taken away by my father when our family split up years ago. This is unbelievable… —And so began a peach-colored, forbidden love between siblings.