A deep, dad and sister brainwashing, we are a sex toy for our new father-in-law.

Yui is a sister who is very caring and does housework, and Karin is a sister who is quiet and easily influenced by her personality. The two lived without any inconvenience with their mother's new wife and wealthy stepfather. However, due to my mother's chronic illness, she experiences nightmares while she is hospitalized... Her stepfather, who was so kind, suddenly changed, revealing her lust and approaching the sisters. My younger sister, who is easily swayed, cleverly guides her to sex. My strong-willed sister forcefully impregnates her. They take advantage of the differences in personality to manipulate them and control their mind and body. Before long, the two had become female slaves competing in sexual service. "Our value is to become a pregnant bag for my father-in-law, I will first, first, first..." I have been brainwashed so much that I can only think of that...