Himari, the older sister, is an honor student, and Hinako, the younger sister, is unable to fit in at school and refuses to go to school. The two lived peacefully with their mother and her stepfather, who was a wealthy man after her remarriage. However, while their mother was hospitalized for childbirth, the house became a space of lust dominated by the stepfather... He skillfully exploited Hinako's inferiority complex and ejaculated inside her. He took advantage of Himari's kindness towards her sister and had sex with her... Before they knew it, the two had become sex slaves, competing to serve their stepfather's dick and fight over him. Their Kokoro and bodies were so dominated that they happily became pregnant, wondering who would get pregnant first...