Incest drama between siblings. Mao lives with her parents and younger brother. One day, her brother becomes a hikikomori due to bullying at his part-time job. The brother, who often sulks at home, starts looking at his sister Mao with lecherous eyes and begins to pressure her into a sexual relationship. The sister, torn by complex emotions, cannot refuse him. Their parents also turn a blind eye to the dark side of their family. Mao becomes isolated in the household and continues to be subjected to her brother's insemination.
