A man who digs into his mother's mysterious death meeting humans with the same faces as him one by one and becoming embroiled in a bigger conspiracy.

20-year-old Jeong-hee doesn't go to college and works part-time. She goes to meet Min-young, her old high school roommate, for the first time in a while and wants to play with her as before. However, Min-young, a college student, is busy sending correction emails for her credits and feels uncomfortable by Jeong-hee's visit.