Uwaki Biyori -Datte Kareshi to Suru yori Kimochi Iin da Mon-

Kuji Kaede who attends Nasumizu Gakuen is an examinee aiming for a national university.”The first sex I’ve ever had with my boyfriend wasn’t so great.” She despaired saying, “This isn’t the sex I was looking for.”She wants to experience the intense pleasure that makes her breathing difficult, and asks her sister Azusa, to introduce her to a man who is good at sex.Thus, Kaede, a serious school girl, begins her promiscuous affairs.[Translated from DLsite]