A pure and innocent girlfriend in a serious relationship gets slept with by a scumbag, only to discover she's a born sex addict. (Kojima Miko MKON-138)

Miko and Yoshio, who had maintained a healthy relationship, were photographed by Saito on their way home from a date. Saito took the photo of Miko handing him a condom and kissing him. He used this to blackmail Miko, eventually leading to them having sex with condoms. Miko subsequently became completely depraved, even begging for unprotected sex, but even so, she refused to break up with Yoshio. Although she verbally claimed to still love Yoshio, she was actually indulging in the immoral pleasure of infidelity. To her, Saito was nothing more than a penis to give her pleasure.