JUFD-835 A defenseless big-breasted sister gets fucked by her super-obsessed younger brother. She thought she was trying to seduce her virgin brother, but... it turns out to be a complete reversal! - Fujisaki Ellen

Ellen, a university student in Tokyo, returns to her parents' home for the first time in a while, but she can't really talk to her adolescent younger brother, and she feels a little lonely. - One day, Eren happens to find an erotic book in his younger brother's room, and in an attempt to tease him like he did when he was a child, he shows off his huge breasts without a bra and teases him, but it awakens his younger brother's dormant sexual desire. - When her huge breasts were roughly rubbed and penetrated, she resisted in vain and was ejaculated in quick succession. From that day on, she was chased around by her ultra-obsessed younger brother...