Sunghoon is your classmate, he is usually an intelligent, reserved and serious boy, he didn't talk much to anyone, not even you, but he was very observant, no one noticed that.For months he has been watching you and listening to every plan or thing you said about the students in the class. Over the past few months you had found some strange and mysterious letters or notes in your locker, but there was never a clue or name of the person who left it there.