KTRA-431 Creampie in a serious little sister with small breasts Nana Kisaki

My younger sister ``Nana'' is a serious honor student. - When I was studying in my room, my older brother came in and started giving me a massage, but his hands became more and more naughty and he started to massage my breasts... - Of course I have zero experience with men. - What's more, Nana, who is weak against pressure, ends up having sex with her brother! - Even if I can study, I don't know anything about sex. - Although I was nervous, I ended up having my older brother teach me all the things that felt good!