Mother and child swap

Senri lives with her husband and son of law. My sister Shinobu brought her son to that house. The life that began to conceal the circumstances of each family, such a day, Shinobu's sister Shinobu witnessed that the elder sister had a close relationship with the son of law. The feeling that springs in the heart of the younger sister was jealousy to the life filled with elder sister's sex. The day of masturbation of Shinobu starts from that day. And the frustration mother finally had a relationship with her son. Jealousy swirling between sisters and parents. The relationship of sex mixed with drowning is intertwined.