An old man who lives alone in the mountains... I wonder if I was looking forward to going every year because it is great nature. However, in fact, the uncle and the mother were paying the debt with their bodies without the young sisters knowing. Kana, the older sister, can't read the situation, but the uncle taunts the younger sister Mana with obscene words like a habit. Kana, who wants to help her sister and mother somehow, accepts the uncle's hopelessly disgusting propensity. However, gradually the disgustingness gradually dominates Kana's body ... myself rather than my sister. I am more concerned about myself than my mother.