“Ah, so it’s you. The one that’s taken my place.” Still keeping their true identities secret, Sooha and Heli return to school as an official couple when suddenly a mysterious girl with Sooha's face named Selen appears. Sooha, with whom they have made countless memories together in the current, and Selen, with whom they share deep and fond memories from the past. As two people who never should have met collide, a dangerous and heartrending romance begins once more.