Mei-chan is a serious and kind girl. Her latest worry is the big boobs she inherited from her mom. Her F-cup breasts cause her stiff shoulders, so her creepy siscon brother is giving her a massage to loosen them up... Her brother can't stand the sight of his sister's well-developed breasts. His hands get more and more erotic as he kneads her big boobs... "Big brother? Is this a massage too?" Mei-chan can't resist pressure, so before she knows it, she's engaged in incest with her brother!