Incest: The older brother secretly watches his younger sister bathe and the blissful ending belongs to the incest genre. The summary discusses how the older brother secretly watches his sister bathe, and the sister is well aware of what her brother wants (seeing "his little guy" standing up). With their parents not home, she decides to "give herself" to her brother, and the two indulge in pleasure together, always keeping an eye on the front door - their parents could come back at any moment...