55T2800355 On days when our parents were away, my sister and I had sex all day long until I ran out of sperm. (Kimino Yuna) - Yuna Kimino

Yuna, a younger sister who has secretly harbored feelings for her older brother since childhood, seduces him with provocative advances, leading them to a forbidden act of incest. Having finally fulfilled her long-held desire, she now demands sex almost daily. And today, once again, their parents are out late into the night. The moment their parents leave, Yuna seeks out her brother. "Let's have sex all day today, okay, big brother?"