When I return home after years away, the person waiting for me is my grown sister, whom I once loved. We used to live almost like lovers, but I fled because I couldn't cope with our forbidden feelings. Now even more beautiful as an adult, she agrees to share our first kiss in five years on one condition: kissing only. Their kisses gradually grow deeper and more desperate until neither can hold back, and they finally cross the line. Once it happens, the adult sibling role-play spirals into an unstoppable secret affair.