Megu is a serious, top-student sister. While she was studying in her room, her brother came in and offered to give her a massage, but his touch became increasingly erotic as he massaged her breasts. Of course, she has no experience with men. Not being able to resist pressure, Megu ends up having sex with her brother! She may be good at studying, but she's terrible at anything sexual. Though she was nervous, she decided to let her brother teach her all the things that feel good!