HBAD-264 My younger sister was raped by her older sister's husband... I never thought my fiance would be taken by my brother-in-law Miki Shibuya

Miki heads to her sister's house to introduce her fiance to her sister, but her brother-in-law catches her eye. She doesn't realize it and ends up seducing him. He rapes her without her sister noticing. From then on, she experiences days of humiliation. Her brother-in-law threatens her, forcing her to satisfy her mother's new husband's sexual needs, even in front of her fiance. However, as she continues to be violated, a change begins to take hold in Miki's emotions.