I'm a college student living with my older brother, and I'm extremely obsessed with my older sister, so I spend my days living with the sexual fetish that only gets me excited about things related to my older sister. One day, Honami, who is about to get married to my older brother, comes to live with us. I'm flustered by how much more beautiful and stylish Honami is than I'd imagined, but she smiles and says, "It's like I've got a little brother! "Think of me as your big sister!" she said...huh, big sister? I see, if she's marrying my brother, then she's my sister! I can't contain my excitement at finally having the "big sister" of my dreams. However, she's my brother's girlfriend, so I try to control myself, but after the bath, Honami starts stretching while showing off her big ass, and even asks me to help her. There's no way I can resist the sight of my sister's sexy big ass...