Shoudou by ISAKI Rika

Summary

Plot: In order to approach a girl who works in entertainment industry, Oga end up forcing friendship with Kunie, her younger brother. While going out for fun, they will discover an extreme attraction between each other. Oga finds Kunie masturbating and that leaves him disturbed… But, at the same time, he can’t help feeling dragged into the moment. This way, Oga end up putting his member, which was already hard, into Kunie’s mouth…