"If we're going to fuck, let's kiss properly first!"

University student Nao is invited by his grandmother, whom he has been estranged from for many years, to spend a summer at her mansion. There, he encounters Yuto, who is called "Kutsuwa" and is used as a plaything by men.

Having lived his life as a prostitute in an old family, Yuto has no sexual morals and accepts pain and pleasure equally. As skilled at sexual play as Yuto is, though, his heart is still pure... And when Nao kisses him...