Jiyeon bid her goodbye to her mom and walked her way to school as usual. After school, while she was walking home from school, she saw an envelope lying on the ground. There was a warning sign on the front of the envelope and it said that the person who found this envelope should not open it. Despite the warning, Jiyeon opened the envelope and found a necklace with the word EXO written on it. All of a sudden, Jiyeon out.