Three years after marriage, husband Yuji came to his parents' house with his wife, Erina, when their first child was born. Erica's father and older sister Yuka lived in the family home. Since Erika became pregnant, Yuji, who had been rejected by her sex and had accumulated in the pool, became even more horny when he saw the gentle and beautiful Yuka. Yuji can't stand just looking at Yuka with an irritating gaze.
