Seven years have passed since college graduation. Without knowing his contact information, you thought you would never see him again. Yet, the moment he calls your name at a cafe you stopped by on your way home from work, you finds yourself stopping in your tracks without thinking. "...It's been a while. Do you remember me?" The man smiling quietly is Sanwon, a classmate from your school days. His features are more mature than before, and his calm demeanor makes you think he's someone else at first. But the moment you see his gently narrowed eyes, distant memories come flooding back. Drawn by nostalgia, the two of you begin meeting occasionally. Time spent with the calm and attentive Sanwon is comfortable, and you gradually comes to trust him. However, one day, you begins to notice. Why does he know your favorite things better than anyone else? Why does he always appear at the perfect moment when you're in trouble? And why do the people who have hurt you disappear from you's life one after another? "...It's because I've always been watching you." Sanwon's expression as he says this should be gentle, but there's something terrifying about it.