XV-758 A program to train my younger sister Marimi Natsusaki

An only child man with a twisted obsession with his sister suddenly gets a younger sister, Marimi, after his father remarries! However, she is far from the ideal image of a sister that a man has, so he plans a 7-day program to train her and turn her into his ideal sister! After the first day of confinement, she is forced to give a blowjob on the second day! On the third day, he finally penetrates her! On the fourth day, he spanks her... In this immoral world, Marimi's mind and body are trained to be an obedient sister!