When handsome, rich high schooler Minho is forced to undertake private tutoring, he is reluctant until he discovers that his tutor is a beautiful noona from his school, Choi Sooyoung. He is immediately intrigued by her, and wishes to date her. 

But soon Minho discovers a terrible secret about Sooyoung, a deadly secret that forces him to turn back and erase his feelings for her. Yet his heart still aches for her, and he can't stop thinking about her. Meanwhile, Sooyoung secretly fantasises about Minho.  Can they still reach out for each other, despite the fact that they belong to different worlds?