愛她的妹妹的Himari計劃在觀光時留在姐姐的房子裡，以進一步促進兩者之間的關係。但是，Himari聽說她妹妹的丈夫不能做女性不能做的性行為……即使摩擦她的乳房也非常糟糕。She thinks that if she continues like her younger sister, the couple will be in danger if she continues like this, and she is worried about the relationship between her husband and wife, and in order to teach her how to massage her breasts, she seduces her brother-in-law's big breasts and sneaks up on the guise of howto sex...
